Bovine tuberculosis (short for “large” cattle") is a chronic disease that most often affects cattle, but can occur in most mammalian species, causing general malaise, coughing and possible death. It can be transmitted to other animals and humans. Tuberculosis owes its name to nodules - tubercles - that form in the lymph nodes of infected animals. For several centuries now, people have been trying in vain to overcome this deadly infection, which was described by the famous Hippocrates.

Bovine tuberculosis or so-called bovine tuberculosis is caused by a specific bacterium Mycobacterium bovis (M. bovis), which is part of the same genus of bacteria as M. tuberculosis (which affects humans) and M. avium (which affects birds). It is believed that bacteria can mutate, taking on each other's shape under certain conditions. The most likely transition is from the cow type to the human type. The main difference between bacteria is their virulence or ability to infect.

Bovine tuberculosis was the most common disease of domestic animals around the world until 1920, when control measures began to be taken in developed countries. However, bovine tuberculosis remains a serious problem for livestock, wild animals and humans to this day.

1. bovis can be killed by sunlight, but the bacterium is able to resist dehydration and is also resistant to most acids and alkalis. M. bovis for a long time remains viable in moist, warm soil. The bacterium survives in livestock feces for 1–8 weeks. Bovine tuberculosis is a zoonotic infection and is transmitted to humans.

Bovine tuberculosis is a contagious disease transmitted by contact with infected animals. the following types:

• cattle;
• wild animals;
• People.

Infection occurs when people or animals inhale droplets that are expelled from the lungs into the air during coughing. The infection is transmitted through direct contact with an open wound caused during slaughter or hunting.

1. bovis has been found in several species of wild mammals. A high level of infection appeared in badgers. Scientists have concluded that badgers are the main source of tuberculosis in livestock.
2. bovis can be transmitted in various ways: airborne droplets, raw milk, saliva, urine. In livestock, excretion of the bacterium begins on day 87 after infection. The infection is introduced through inhalation (if livestock is kept indoors) or eating (in the case of badgers). Having appeared in the herd, the infection continues to be transmitted from animal to animal by airborne droplets. Transmission from cow to calf can occur through milk or colostrum.

The tuberculosis process takes a long time; an animal manages to infect many individuals in its herd before clinical signs of the disease begin to appear.

Thus, the main ways of spreading bovine tuberculosis are:

1. The presence of animals in the herd with an undiagnosed disease.
2. Contact with wild animals.

In general, animals are more susceptible to infection with M. bovis under conditions of insufficient nutrition and increased stress. Young individuals fall into the high-risk category. There is confirmed evidence that particularly large dairy farms are more likely to encounter such difficulties.

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• Congratulations! The likelihood that you will develop tuberculosis is close to zero.

  But don’t forget to also take care of your body and undergo regular medical examinations and you won’t be afraid of any disease!
  We also recommend that you read the article on.

• There is reason to think.

  It is impossible to say with certainty that you have tuberculosis, but there is such a possibility; if it is not Koch bacilli, then there is clearly something wrong with your health. We recommend that you immediately go through medical examination. We also recommend that you read the article on detecting tuberculosis in the early stages.

• Contact a specialist urgently!

  The likelihood that you are affected by Koch bacilli is very high, but it is not possible to make a diagnosis remotely. You should immediately contact a qualified specialist and undergo a medical examination! We also strongly recommend that you read the article on detecting tuberculosis in the early stages.

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Does your lifestyle involve heavy physical activity?

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   How often do you take a tuberculosis test (eg Mantoux)?

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   Do you carefully observe personal hygiene (shower, hands before eating and after walking, etc.)?

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   Do you take care of your immunity?

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   Have any of your relatives or family members had tuberculosis?

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   Do you live or work in an unfavorable environment (gas, smoke, chemical emissions from enterprises)?

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   How often are you in damp, dusty or moldy environments?

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   How old are you?

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   What gender are you?

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   Have you recently experienced a feeling severe fatigue for no particular reason?

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    Have you been feeling physically or mentally unwell lately?

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    Have you noticed a weak appetite lately?

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    Have you recently noticed a sharp decline in your healthy, plentiful diet?

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    Have you recently felt an increase in body temperature for a long time?

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    Are you having trouble sleeping lately?

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    Have you noticed increased sweating lately?

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    Have you noticed yourself looking unhealthy lately?

Symptoms of bovine tuberculosis in livestock usually take several months to develop. How long the incubation process will take is unknown, since the infection can remain in the body for years and wait for the right moment: stress, decreased immunity, old age.

The pathogenesis of tuberculosis is predominantly chronic, debilitating animals over a long period of time, but sometimes the disease takes acute forms and progresses rapidly. In the early stages, the pathological process is asymptomatic.

In later stages, common symptoms include:

• progressive exhaustion;
• low-grade fever;
• weakness;
• lack of appetite.

In animals with lung damage, the disease provokes wet cough with increased intensity in the morning, in cold weather and during physical activity. IN in rare cases shortness of breath or rapid shallow breathing is noted.

In the final stages, the animals are severely emaciated and experience increasing difficulty breathing. In some animals, the retropharyngeal or other lymph nodes become enlarged, which can lead to their rupture and leakage of fluid into the surrounding tissue. Significantly enlarged lymph nodes can obstruct the passage of blood vessels, airways and the digestive tract. With disorders of the digestive tract, diarrhea and constipation periodically occur.

In deer, bovine tuberculosis is characterized by a subacute or chronic course with varying rates of progression. Some animals may show only one symptom for several years - suppuration of the lymph nodes. In other cases, on the contrary, the disease can spread from lightning speed.

Cats can also become infected with tuberculosis through unpasteurized milk and contact with animals.

The symptoms are mostly the same:

• weight loss;
• low-grade fever;
• dehydration;
• lack of appetite;
• cases of vomiting or diarrhea.

If the respiratory tract is affected, the cat may develop coughing, shortness of breath, and wheezing. Breathing problems may be associated with physical activity. IN abdominal cavity Enlarged mesenteric lymph nodes can be palpated. Cats are also prone to skin infections in the form of small swellings or flat sores that appear primarily on the face, neck, or shoulders. In some cats, bovine tuberculosis manifests itself as a deformed forehead or bridge of the nose. In later stages, such infections can destroy the bones of the nose and muzzle. Atypical form Tuberculosis in cats primarily affects the eyes. The first symptom is blindness or abnormal pupillary reaction. Retinal detachment and changes in the vitreous may occur. When the anterior parts of the eye are affected, the iris thickens and becomes discolored. In the later stages of the disease, pericorneal hyperemia, vascularization and conjunctivitis can be detected. Suppuration may appear in the periorbital tissues. A person can become infected with tuberculosis from a cat, just like from any other infected animal.

According to statistical studies, the incidence of bovine tuberculosis among people around the world is about 3.1% of the total number of infected people. Of these, 2.1% are pulmonary tuberculosis and 9.4% are extrapulmonary.

The tuberculosis process is characterized by the formation of granulomas (tubercules) in places where the bacterium is localized. Granulomas are usually yellowish in color, curdled or partially calcified. Some tubercles are so small that when opened, they cannot be seen with the naked eye without cutting the tissue.

In cattle, tubercles are localized in the lymph nodes, mainly in the head and chest. They can also be found in the lungs, spleen, and liver. Sometimes numerous small granulomas affect several organs at once. In countries with disease control programs, necropsy of infected animals typically reveals a small number of lesions. Most of them are localized in the lymph nodes associated with the respiratory tract.

To detect infection with bovine tuberculosis during life, several diagnostic methods are used.

1. Clinical diagnosis.
2. Differential diagnosis.
3. Laboratory research.

Diagnosis of tuberculosis is a complex undertaking. Alone clinical signs not enough for staging accurate diagnosis. In developed countries, symptoms of the disease are rare, as most cases are diagnosed on early stages through laboratory testing or are detected through post-slaughter examinations of meat.

Differential diagnosis is a method by which diseases with similar symptoms are excluded.

To detect tuberculosis in animals, the following diseases must be excluded:

• contagious pleuropneumonia of cattle;
• pasteurellosis and pneumonia caused by corynebacteria;
• aspiration pneumonia;
• traumatic pericarditis;
• pseudotuberculosis or pneumoenteritis in small ruminants;
• liver fluke infection.

First of all, infectious diseases of the lungs are excluded, then inflammation and helminthic infestations.

To identify animals infected with M. bovis, the method of intradermal tuberculinization is usually used. This is a tuberculin test containing M. bovis antigens, which are called purified protein derivative (PPD). Subcutaneous tuberculinization is a highly sensitive, specific test, but requires 48 to 72 hours to process and requires specially trained veterinarians to perform the test.

Tuberculinization of cattle is carried out twice a year: in spring and autumn. Tuberculin is injected into the skin of the animal's neck or sub-caudal fold. The reaction is determined 72 hours after injection. An animal is considered infected when the skin fold thickens by more than 3 mm.

An intradermal test is an allergic diagnostic method, so the result largely depends on the immunity, age, and condition of the animal. Sometimes the reaction is mild or absent altogether

.

Another method for determining M. bovis is the examination of milk samples. The test is quite sensitive and accurate, but requires significant labor costs and more than six weeks to identify the disease.

Diagnosis of microbacterial infections is most effective when using this laboratory research, like sowing. However, identification of M. bovis by culture is a labor-intensive and time-consuming process. In addition, molecular technologies are expensive, since their application requires appropriate laboratory equipment and qualified personnel.

In cattle, the lesions are most often localized in the lungs and lymph nodes. Tuberculosis primarily affects the lower respiratory tract, although there are also many cases of infection of the upper respiratory tract and surrounding tissues.

The final diagnosis is established by isolating and identifying the causative agent (M. bovis) from the lymph nodes or lungs of animals during necropsy or after slaughter. For these purposes, a combination of traditional sowing with biochemical methods is used. This is painstaking, time-consuming work. It may take more than 90 days to grow a microorganism, and another two weeks will be spent on its biochemical identification. Molecular methods look promising, especially the polymerase assay chain reaction(PCR). However, the success of a PCR test depends on how pure the resulting DNA sample is.

Infected animals cannot be treated - they are isolated and sent for slaughter. Some species have been treated, but the treatment has been too long and clinical improvement can occur without the use of drugs. The high risk of spreading the disease, infecting people and the resistance of microorganisms to the drug put treatment into question. There are countries where, for these reasons, treatment of animals with tuberculosis is prohibited by law.

Prevention of tuberculosis for farms containing cattle includes the following measures:

1. Periodic tuberculinization of domestic cattle with subsequent elimination of disease carriers.
2. Checking meat at slaughterhouses. After slaughter, meat is checked for the presence of tubercles in the lungs and lymph nodes. This is done to ensure that infected meat does not end up in human food, and also so that veterinarians can trace the path of infection of the animal and identify other sick animals.
3. Compliance with established sanitary standards when working with animals.
4. Establishing quarantine when infected animals are detected.
5. Sanitation and disinfection measures reduce the risk of infection within the herd. The bacterium M. bovis is relatively resistant to disinfectants, so it requires prolonged contact with active substance. The most effective products are those containing 5% phenol solution, solutions with high concentration iodine, glutaraldehyde and formaldehyde. M. bovis is susceptible to exposure to humid heat of 121°C for at least 15 minutes.
6. On farms where cases of bovine tuberculosis have been detected, rodent control measures are recommended.
7. Keeping livestock under favorable conditions.
8. Restricting access of wild animals to the farm: installing fences around hay storage areas, taking measures to bioprotect the farm.

There is no effective vaccine for animals against bovine tuberculosis yet. However, new types of vaccines are being developed and tested - mainly for wild animals.

Vaccination of livestock to control the spread of bovine tuberculosis is not used and is prohibited in the European Union. This is due to the fact that when using the BCG vaccine, it is useless to carry out a tuberculin test, since it is impossible to determine whether the animal has been infected or vaccinated against tuberculosis.

To effectively combat tuberculosis, in 1988, “Instructions on measures for the prevention and elimination of animal tuberculosis” were developed.

The number of people infected with bovine tuberculosis has decreased significantly in countries with pasteurized milk and tuberculosis control programs in place. However, bovine tuberculosis is still diagnosed in humans where proper measures are not taken to control the spread of tuberculosis. Farmers, slaughterhouse workers and other personnel who work directly with animals are at high risk. In addition, wildlife can be a source of infection, especially where wild animal meat is consumed. Boiling and cooking foods completely destroys the bacterium that causes bovine tuberculosis.

Sometimes people become infected without symptoms. In other cases, the disease can develop either immediately after the bacteria enters the body, or several years later when the immune system is weakened. Tuberculosis can be localized in the lymph nodes, skin, bones and joints, urinary and reproductive systems e, brain and respiratory tract.

There are claims that the symptoms of bovine tuberculosis in humans differ from the usual course of the disease. Children infected with the bacterium M. bovis have typical symptoms abdominal infections, whereas in adults they often become inflamed cervical lymph nodes- sometimes with signs of ulceration.

Other sources state that the symptoms of M. bovis in humans are no different from those of tuberculosis caused by the bacterium M. tuberculosis. The problem is that in order to determine which bacterium causes tuberculosis - M. tuberculosis or M. bovis, special laboratory tests must be carried out.

Early in the course of the disease, tuberculosis can be confused with a common viral infection.

Among the most common symptoms:

• chronic fatigue;
• weakness;
• weight loss;
• dry cough, worse at night and early in the morning;
• low-grade fever.

One of the indicative symptoms of tuberculosis is blood in the sputum. However, in this case it is important to exclude acute heart failure and lung tumor. In the acute period, a sick person may experience pain in the chest and behind the shoulder blades.

Tuberculosis, in addition to the lungs, can affect any other organ. In this case, symptoms such as:

• from the genitourinary and reproductive systems: blood in the urine, aching pain in the lower abdomen and spotting in women;
• from the central nervous system: headaches, dizziness, fainting;
• from the digestive tract: diarrhea, constipation, bloating, blood in the stool.

These forms of the disease are rare compared to pulmonary ones, and these manifestations are more difficult to diagnose, since they can be associated with a number of other diseases.

Drinking raw, unpasteurized milk is dangerous as it can lead to contracting tuberculosis from the cow. This is especially true for children - an unformed organism is most susceptible to dangerous infections.

A few facts about tuberculosis:

1. Robert Koch discovered the tuberculosis bacillus in 1881. The bacterium M. bovis was identified in 1898.
2. World Tuberculosis Day is celebrated on March 24: it was on this day that Robert Koch announced his discovery.
3. It is no coincidence that the bacterium M. bovis was called a rod. If you look at the photo with her image, you can note the similarity of shapes.
4. Pasteurization of milk from infected animals has significantly reduced the incidence of bovine tuberculosis in humans.
5. In 2016, the mortality rate from tuberculosis in Russia decreased by 15% - almost half compared to 2015.
6. Bovine tuberculosis remains a serious public health problem for humans and animals in many developing countries.

Tuberculosis is one of the the most dangerous infections in the world. Thanks to vaccination and preventive measures developed by healthcare organizations, positive results have recently been achieved in the fight against infection.

WHO plans to completely eliminate tuberculosis by 2030. Over the past two decades, the death rate and prevalence of tuberculosis worldwide have fallen by almost half.

Quiz: How susceptible are you to tuberculosis?

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• Congratulations! You're doing well.

  The probability of getting tuberculosis in your case is no more than 5%. You are completely healthy person. Continue to monitor your immunity in the same way and no diseases will bother you.

• There is reason to think.

  Everything is not so bad for you; in your case, the probability of getting tuberculosis is about 20%. We recommend that you take better care of your immunity, living conditions and personal hygiene, and you should also try to minimize the amount of stress.

• The situation clearly requires intervention.

  In your case, everything is not as good as we would like. The probability of infection with Koch bacilli is about 50%. You should immediately contact a specialist if you experience first symptoms of tuberculosis! It is also better to monitor your immunity, living conditions and personal hygiene, and you should also try to minimize the amount of stress.

• It's time to sound the alarm!

  The probability of infection with Koch sticks in your case is about 70%! You need to contact a specialist if any unpleasant symptoms appear, such as fatigue, weak appetite, or a slight increase in body temperature, because all of this may turn out to be symptoms of tuberculosis! We also highly recommend that you undergo a lung examination and do a medical test for tuberculosis. In addition, you need to take better care of your immunity, living conditions and personal hygiene, and you should also try to minimize the amount of stress.

Tuberculosis (Tuberculosis) is an infectious, chronic disease of all species of animals and humans, characterized by the formation of specific nodules in various organs that are exposed to caseous necrosis and calcification.

Historical background. Tuberculosis has been known to mankind since ancient times. Hippocrates (4th century BC) described the clinical signs of tuberculosis in humans and recommended treatment methods. The term “tuberculosis” was first used by the French physician Lenek (1819) in 1869. Villemin established the infectiousness of tuberculosis.
The causative agent of the disease was discovered by R. Koch in 1882. In 1890, he produced the diagnostic drug tuberculin.

In 1924 And Calmette and S. Guerin produced the BCG vaccine - for specific prevention tuberculosis in humans.
Tuberculosis is registered in many countries of the world. In Russia, the prevalence of tuberculosis among animals is insignificant.
Eradication of tuberculosis is a serious problem and is especially urgent because the disease is zoonotic and anthropozoonotic.

Economic damage. Tuberculosis causes great economic damage to livestock production, which is associated with a decrease in productivity, premature culling and delivery of animals for slaughter, lengthy and expensive anti-epizootic measures and other material costs.

The causative agent of the disease-Mycobacterium tuberculosis, a rod from 0.5 to 8µ long, often bent at an angle, sometimes appears in the form of grains located in one line. The microbe is a strict aerobe, non-motile, does not form spores, acid-resistant, and also alcohol- and antimorphine-resistant. The acid-fastness of the tuberculosis bacillus is used to differentiate it from other non-acid-fast bacteria. The tuberculosis bacillus contains fat wax and therefore does not accept paint well, but, being colored with carbolfuchsin when heated, it retains this paint better than other microorganisms. When smears are treated with a weak solution of sulfuric acid, tuberculosis bacteria are not discolored (they are stained magenta red), but other microbes are discolored (Ziehl-Neelsen method). In smears they are located singly or in groups.

There are three known types of tuberculosis bacillus: human (humanus), bovine (bovines), avian (avium), which are varieties of the same species. Under certain conditions, they can sometimes change, turning into other types. Most often there is a transition from the bull type to the human type. In 1937, Wales isolated a special type of bacteria from the field mouse, called the Oxford strain. This strain is close to the bovine type. Other scientists consider it the fourth type of tuberculosis bacillus - mouse.

The main difference between the types is their unequal virulence for individual species animals and humans.

Mycobacterium tuberculosis (human species) causes tuberculosis in humans. TO this species Pigs, cats, dogs, cattle, and fur-bearing animals are also susceptible to mycobacteria, but birds (with the exception of parrots) are not susceptible.

Micobacterium bovis (bovine species) causes tuberculosis in all types of agricultural and wild animals, including fur-bearing animals, as well as humans. Birds are not susceptible to this type of mycobacteria.

Mycobacterium avium (avian species) causes tuberculosis in domestic and wild birds; pigs are susceptible to this type of mycobacterium; Animals of other species and humans are rarely infected.
In nature (in peat and soil) there are opportunistic atypical and saprophytic mycobacteria, which in their morphological and cultural properties are close to avian mycobacteria.

Animals infected with such mycobacteria can react to tuberculin for mammals, which is used by practical veterinarians when carrying out planned anti-epizootic measures, which causes certain difficulties when carrying out allergic diagnosis of tuberculosis.

Due to the content of fatty wax elements, the tuberculosis bacillus is very resistant to the external environment and to the effects of disinfectants. In air-dried pieces of affected lungs, microbes remain virulent for 200 days, and in soil and manure they remain viable for up to 4 years, and in birds for up to 10 years. Sunlight disinfects bacteria in sputum only after 72 hours. In products obtained from sick animals, the tuberculosis pathogen persists: in milk for up to 19 days, in butter for up to 300 days, in cheese for 145-200 days, in frozen meat for up to 1 year, in salted meat for 60 days. In the carcasses of cattle and birds, mycobacteria persist from 3 to 12 months.
Heat has a detrimental effect on tuberculosis bacteria. Heating milk to 55° kills them after 4 hours, to 85° kills them after 30 minutes; when milk is boiled, mycobacteria die after 3-5 minutes.

Chemicals have a detrimental effect on bacteria over relatively long periods of time: a 5% solution of carbolic acid - after 24 hours, a 5% formaldehyde solution - after 12 hours, a solution containing 5% active chlorine - after 3 hours.
The best disinfectants are a 3% alkaline solution of formaldehyde (exposure 1 hour), a suspension of bleach containing 5% active chlorine, a 10% solution of iodine monochloride, a 20% suspension of freshly slaked lime, a 5% solution of calcium hypochloride, 1 % solution of glutaraldehyde and other preparations.

Epizootological data. More than 55 species of domestic and wild animals and about 25 species of birds are susceptible to tuberculosis. The most susceptible are cattle and pigs, fur-bearing animals are minks, and chickens are among birds. Less commonly, goats, dogs, birds, ducks and geese get sick with tuberculosis. Sheep, horses, and cats very rarely get sick.
The main source of infectious agents for tuberculosis are sick animals. They excrete bacteria in feces, sputum, milk, and, if the genitourinary tract is affected, in semen. In cattle with pulmonary tuberculosis, there may be up to 100,000 tuberculosis bacteria in 1 g of sputum. When coughing, part of the sputum is sprayed into the air, and part is swallowed by animals and comes out with feces. A cow with tuberculosis is capable of excreting an average of 37 million tuberculosis bacteria per day in feces. The secretions of animals suffering from tuberculosis infect environment: premises, walking yards, pastures, watering places.

Factors of transmission of the infectious agent can be feed, water, bedding, manure, etc.

Infection with tuberculosis occurs more often during the stall period when animals are kept in crowded conditions. Young animals become infected mainly through milk and skimmed milk obtained from sick animals. Maybe intrauterine infection calves Animals can become infected through contact with people with tuberculosis, especially milkmaids and calves who do not undergo annual medical examinations. On the pasture, infection is less common, since the bacteria die under the influence of sunlight, but if the summer is rainy and cold, then mass reinfection of animals is possible on the pasture. During the stall period, adult cattle are infected mainly by aerogenous means, while on pasture they become infected through nutritional means; pigs become infected by feeding them undisinfected kitchen waste from hospitals, tuberculosis dispensaries, or by contact with sick birds. Dogs and cats - from people suffering from an open form of tuberculosis or from eating milk and meat from sick cows.

Poor living conditions malnutrition, excessive exploitation reduces the resistance of animals to tuberculosis. Sharp transitions from one living conditions to others, changes in feed, and lack of regular exercise during the period also have a negative impact. fresh air, cramped and damp rooms and other unsanitary conditions for keeping animals.

In beef cattle kept in the steppes, the incidence of tuberculosis is insignificant. However, once livestock are deprived of the conditions to which they are accustomed, resistance to tuberculosis falls and the livestock gets sick.

In herds, tuberculosis usually spreads slowly, with massive re-infection of livestock occurring over several months. The comparatively slow spread of tuberculosis is explained, on the one hand, by the length of the incubation period, and on the other, by the fact that not all sick animals are active bacteria excretors.

Most often, a certain number (sometimes significant) of sick animals is detected in the spring, when the veterinary service carries out routine tuberculinization on farms, but sometimes livestock is re-infected on pasture, especially if the summer is damp and cold.

Pathogenesis. Having penetrated the animal's body with inhaled air or through the digestive tract, tuberculosis bacteria enter the lungs or other organs through the lymphogenous and hematogenous routes. At the site of localization of tuberculosis bacteria, it develops inflammatory process with the subsequent formation of tuberculous nodules - tubercles the size of a lentil grain, grayish in color, round in shape. In the center of the tubercle, dead cells under the influence of mycobacterial toxins turn into a curdled mass.
Depending on the resistance of the organism and the virulence of the bacteria, the tuberculosis process can be benign or malignant.

In a resistant organism, tuberculosis bacteria are surrounded by epithelioid cells, from which giant cells are subsequently formed. This entire group of cells is surrounded by a ring of lymphocytes. Exudate is deposited between the cells and fibrin coagulates. The developing avascular tuberculous tubercle (granuloma) is encapsulated. Tissue cells in the tubercle die due to lack of influx nutrients, and under the influence of bacterial toxins, a curdled mass is formed, impregnated with lime salts. With such a benign course of the disease, in such an encapsulated focus, tuberculosis bacteria in after all may die and further development infectious process stops.

In cattle, tuberculosis of the serous membranes (pleura, peritoneum) - “pearl oyster” - is quite often observed. In this form of the disease, inflammation from the very beginning is productive. Tuberculous tubercles undergo fibrinous degeneration and turn into dense shiny growths.

In an organism with reduced resistance, the process of delimitation and localization of the tuberculosis pathogen is weakly expressed. Due to insufficient encapsulation, melting of the walls of tuberculous nodules occurs. Mycobacteria enter healthy tissue, which leads to the formation of new small (miliary) nodules. The latter merge with each other and form large tuberculous foci. If the cheesy mass is released from these foci, for example in the lungs through the bronchi, then cavities are formed. The pathogen spreads through the lymphatic vessels; when it hits circulatory system bacteremia occurs in the animal's body. Bacteria spread throughout the body, the process generalizes, and many organs are affected (liver, kidneys, spleen, etc.).

The resistance of an animal's body depends not only on its initial state, but also on the conditions in which it is located. If there are favorable feeding and housing conditions on the farm that increase the body's resistance, the onset of development of the tuberculosis process can be delayed at a certain stage. Even large tuberculosis foci can be subject to encapsulation and calcification in the body of animals. Immuring the causative agent of tuberculosis either leads to the suppression of its reproduction, or ends in the death of the pathogen, and then the body of the sick animal recovers.

In the case of generalization of the tuberculosis process and extensive lung damage, gas exchange is disrupted, toxins of tuberculosis bacteria reduce erythropoiesis, which causes anemia. If this is accompanied by intestinal lesions, accompanied by impaired absorption of nutrients, then the animal suffers exhaustion and death.

Course and symptoms of the disease. The duration of the incubation period for tuberculosis ranges from two to six weeks. Tuberculosis in animals is chronic or latent, so clinical signs of the disease may appear several months or even years after infection.

The onset of tuberculosis disease in animals in private household plots, peasant farms and agricultural enterprises is determined during routine diagnostic tests for tuberculosis (tuberculinization) by veterinary specialists based on the presence of positive allergic reactions.
When animals that react positively are sent for diagnostic slaughter, and during post-mortem examination of organs and lymph nodes, signs characteristic of tuberculosis are found.

Conventionally, a distinction is made between active, or open, tuberculosis, when tuberculosis bacteria are released with bronchial mucus, feces or milk, and latent tuberculosis, when the bacteria are so isolated in the tuberculosis focus that they are not released outside.

When the intestines, udder and uterus are affected, the tuberculosis process is always open; when the lungs are affected - not always, but very often. Based on the location of the pathological process, pulmonary and intestinal forms of tuberculosis are distinguished; In addition, animals also have lesions of the udder, serous integument (pearl mussel), genital form and generalized tuberculosis. The course of the disease in individual animals is generally similar, but there are some peculiarities.

In cattle Tuberculosis is mostly chronic or latent. In young animals - acute and subacute. Clinical signs of the disease are: increased body temperature (39.5-40°C), wet cough, especially in the morning. The mucus released when you cough sometimes contains pieces of dead tissue. Sick animals experience shortness of breath. Auscultation of the chest in the lung area reveals wet or dry rales. If an animal's pleura is affected by the tuberculosis process, the animal will experience pain when pressing between the ribs. A sick animal loses weight. The skin becomes dry and loses elasticity.

With generalized tuberculosis, the lymph nodes (submandibular, retropharyngeal, parotid, cervical, prescapular, inguinal, knee fold, suprauterine) become enlarged. When palpated, the affected lymph nodes are dense, sometimes lumpy, and painful. An enlargement of the mediastinal nodes leads to compression of the esophagus, and this disrupts the belching process and causes chronic swelling of the rumen.

If the udder of animals with tuberculosis is affected, then part of it, usually the back, swells, becomes painful and hard. Milk mixed with blood or curdled mass is squeezed out of the nipples.

When the intestines are affected, intermittent diarrhea is initially observed, which then becomes constant. A sick animal develops cachexia. Damage to the uterus and vagina is accompanied by abortion, nymphomania, barrenness. A glassy discharge mixed with pus is released from the vagina. Damage to the genital organs in bulls is complicated by orchitis. A pearl oyster can be identified on the pleura by auscultation.

The tuberculosis process, as a rule, progresses slowly. The disease can last for many years. Some sick animals recover, and in cases where the primary complex becomes sterile, the animal loses sensitivity to tuberculin. Most animals with tuberculosis appearance and general condition are no different from healthy ones. Tuberculosis lesions are found only at slaughter.

Horses suffer from tuberculosis relatively rarely, mainly on farms where cattle suffer from tuberculosis, and the disease most often occurs latently. If the tuberculosis process is severe, severe emaciation of the animal is noted, although the appetite may persist for a long time. When the lungs are affected, a weak cough appears, and the horse quickly gets tired of working. In some cases, there have been cases of damage to the nasal mucosa with the presence of nodules and ulcers.

Young horses have tuberculosis of the intestines and mesenteric lymph nodes. In this case, we notice poor appetite and colic appears. Constipation gives way to severe diarrhea. Equine tuberculosis is characterized by polyuria, the amount of urine excreted increases 3-4 times.

Porcine tuberculosis observed in farms where there are cattle or poultry with tuberculosis. The disease in pigs is predominantly asymptomatic. The most characteristic clinical signs are enlargement of the submandibular, retropharyngeal and cervical lymph nodes. Sometimes abscesses form in these nodes, after opening which fistulas remain, from which a purulent-curdled mass is released. If the lungs are affected, coughing and vomiting, difficulty breathing are observed, and if the intestines are affected, diarrhea occurs. Sick pigs lose weight quickly.

In sheep and goats Tuberculosis basically proceeds in the same way as in cattle. More often the disease is asymptomatic. With a highly expressed tuberculosis process, patients experience coughing, nasal discharge, and emaciation. In goats, udder damage is characterized by the formation of hard, lumpy swellings, sometimes reaching a significant size.

Avian tuberculosis. Chickens get sick more often, geese and turkey ducks much less often. The disease is chronic with very unclear clinical signs. Sick chickens become lethargic and lose weight while maintaining their appetite. The crest becomes pale and wrinkled, the bird is inactive, egg production decreases, and the pectoral muscles atrophy. Generalization of the tuberculosis process is accompanied by damage intestinal tract. Vomiting and diarrhea are observed, causing severe exhaustion of the bird. Sometimes bones and joints are affected, and lameness is noted. A sick bird develops anemia: the number of red blood cells drops to 1 million, the hemoglobin content to 35%.

Canine tuberculosis. In dogs, tuberculosis is characterized by low-grade fever, decreased appetite, lethargy, and gradual emaciation of the animal. There is a cough and nasal discharge. If the intestines are affected, diarrhea occurs. Due to tuberculosis, dogs may develop synovitis and deforming osteoarthritis. Death occurs from complete exhaustion.

Camel tuberculosis. The cervical and submandibular lymph nodes are affected; There is a cough, increased sweating, and rapid fatigue.

From fur animals Silver-black foxes, minks and nutria are susceptible to tuberculosis. Young animals get sick more often. The disease is predominantly chronic; weakness, lethargy, and progressive emaciation are noted. When the lungs are affected, coughing, difficulty and rapid breathing are observed. If the intestines are affected, diarrhea and, less commonly, constipation appear. Liver damage may be accompanied by jaundice. Foxes sometimes develop non-healing ulcers on the skin of their necks.

Pathological changes. In large and small cattle, tuberculosis most often affects the lungs and bronchial-mediastinal lymph nodes.

According to P.I. Kokurichev (1950), lymph nodes in a cattle patient with tuberculosis chest cavity affected in 100%, lungs in 99% of cases; other organs - rarely: liver - 8%, spleen - 5%, udder - 3%, intestines - 1%.

When opening the lungs, dense foci of a reddish-gray or yellowish color are found. The contents of the lesions are cheesy or calcareous. Sometimes the lesions look like purulent foci surrounded by a thin connective tissue capsule. Around such foci are scattered nodules of various sizes, from a pinhead to a millet grain. The presence of cavities surrounded by a dense capsule is also characteristic. Tuberculous foci can be found, although much less frequently, also in other parenchymal organs, in the bone marrow and bones. The pleura is also affected, and sometimes fusion of its leaves is observed. The so-called pearl mussel is characterized by the formation of small tuberculous nodules on the serous membranes of the chest and abdominal cavities with the simultaneous proliferation of connective tissue. A cluster of dense nodes looks like cauliflower. On a section of the lymph nodes affected by tuberculosis, a curdled degeneration is detected. On the mucous membrane of the pharynx, small intestine and cecum, individual tubercles and ulcers of various sizes are observed, having a hard bottom, they are covered with a dry cheesy mass.

When autopsying the corpses of adult horses that died from tuberculosis, changes are found mainly in the lungs, often in the form of a miliary process. In foals, damage to the mesenteric lymph nodes is noted. The latter are enlarged, and numerous cheesy-purulent foci are found in them. Nodes and ulcers are found on the intestinal mucosa. If the liver and spleen are affected by the tuberculosis process, they can be enlarged several times. In horses, damage to the serous membranes (pearly mussel) is also observed.

When autopsying birds that have died from tuberculosis, specific lesions are often found in the liver and spleen in chickens, and in the lungs in geese and ducks.
The liver and spleen are usually sharply enlarged, have a flabby consistency and contain numerous tubercles located both in the depths and along the periphery of the organ. Tuberculosis foci of various sizes are sometimes found in large numbers in the small and large intestines, where they are located in the mucous membrane and submucosal layer. There may be ulcers on the mucous membrane various sizes. The lymph nodes of the mesentery are enlarged and contain caseous masses. In rare cases, tuberculosis lesions are found in the kidneys and bones.

Diagnosis Tuberculosis is diagnosed comprehensively, taking into account epizootic data, clinical signs and the results of allergic, pathological, histological, bacteriological and biological studies.

The clinical diagnostic method is of limited value, since in relation to large species Animals using this method manage to isolate very few patients with tuberculosis.

The main method of intravital diagnosis of tuberculosis is allergic. Allows you to identify patients with any form of tuberculosis, regardless of whether the animal has clinical signs of the disease or not.

To diagnose tuberculosis in cattle, buffaloes, pigs, goats, sheep, horses, camels, dogs, monkeys and fur-bearing animals, tuberculin is used - a sterile filtrate of killed cultures of the tuberculosis pathogen of two types: dry purified (PPD) tuberculin for mammals and PPD - tuberculin for birds. Tuberculin PPD for birds is prepared from the causative agent of avian tuberculosis and is used for the diagnosis of tuberculosis in birds and pigs.

The main intravital method for diagnosing tuberculosis in animals is an allergic intradermal tuberculin test. In horses, camels, and buffaloes, diagnosis is carried out using the eye method (ophthalmic test). If necessary, an ophthalmic test is also carried out in cattle simultaneously with an intradermal test.

Tuberculinization is subjected to:

• cattle (buffaloes) twice a year: in the spring, before pasture, and in the fall, before placing livestock for winter maintenance, and young cattle from 2 months of age, cattle of fattening groups - once a year;
• horses, mules, donkeys, sheep and goats - depending on the epizootic situation;
• all adult sows, as well as young animals after weaning in all breeding farms - once a year, and on other pig farms - depending on the epizootic situation;
• adult birds (over two years old) of original lines and ancestral flocks at breeding factories and breeding poultry stations - once a year.

Animals belonging to citizens living on the territory of farms or in individual settlements are examined for tuberculosis simultaneously with tuberculinization on the farm.

With the intradermal method of tuberculinization, tuberculin is injected into the middle of the neck of cattle, buffalo, zebu, deer (deer) in the middle of the neck, in bulls - under the tail fold, in camels - in the area of ​​the outer surface of the ear 2 cm from its base, in goats - in the thickness lower eyelid; dogs, monkeys and fur-bearing animals (except minks) - to the region inner surface thigh or elbow crease; mink - intrapalpebrally in upper eyelid; for cats - in the area of ​​the inner surface of the ear; for chickens - in the beard; for turkeys - in the submandibular earring; for geese, ducks - in the submandibular fold; for male pheasants - in the cavernous bodies of the head; peacocks, parrots, pigeons, cranes, herons, storks, flamingos - in the area outside shins 1...2 cm above the ankle joint.

Before tuberculin is administered, the fur (hair) at the injection site is trimmed (feathers are plucked), and the skin is treated with 70% ethyl alcohol.

Reading of the reaction to intradermal injection of tuberculin is carried out in cattle, buffaloes, zebu cattle, camels and deer in 72 hours; in goats, sheep, pigs, dogs, cats, monkeys, fur-bearing animals in 48h; in a bird in 30-36 hours. In areas unaffected by tuberculosis, cattle and camels are allowed to re-inject tuberculin 72 hours after the first administration in the same dose and in the same place. The response to repeated administration is recorded and assessed after 24 hours.

When taking into account the intradermal reaction, the site of tuberculin injection is palpated in each animal under study; in minks, the eyelids of the left and right eyes are visually compared.

If, during reading, thickening of the skin is detected at the site of tuberculin injection in cattle, buffalos, zebu cattle, camels, deer, we take a cutimeter and measure the thickness of the fold in millimeters and determine the magnitude of its thickening, comparing it with the thickness of the fold of unchanged skin near the site of tuberculin injection.

Animals are considered tuberculin responsive:

• cattle (except bulls), buffalo, zebu, camels, deer, deer, antelope - with thickening of the skin fold by 3mm or more regardless of the nature of the swelling (swelling, pain, increased local temperature);
• bulls, sheep, goats, elephants, rhinoceroses, hippopotamuses, pigs, dogs, wolves and other representatives of carnivores, birds, dolphins, cats – when swelling forms at the site of tuberculin injection.

Intradermal tuberculin test - a highly specific reaction to tuberculosis. At the same time, it depends on the general immunoreactivity of the body. In old, deep-pregnant animals, in animals with low fatness, as well as in generalized tuberculosis, the reaction to tuberculosis may be weakly expressed or absent altogether (anergy).

Veterinary specialists conducting tuberculinization should keep in mind that sometimes nonspecific (para- and pseudo-allergic) reactions to tuberculin for mammals are possible, due to sensitization of the body by avian mycobacteria, pathogens of paratuberculosis and atypical mycobacteria, as well as other reasons. To differentiate nonspecific reactions, a simultaneous allergy test is used, which is carried out simultaneously with tuberculin for mammals and a complex allergen from atypical bacteria (CAM). If, when reading the reaction, the intradermal reaction to the administration of CAM is more intense than to tuberculin for mammals, veterinary specialists consider the reaction to be nonspecific, material from such animals is examined for tuberculosis laboratory methods.
Tuberculinization by the eye method (ophthalmotest) is used to diagnose tuberculosis in horses and other representatives of equids.

In cattle, this method can only be used simultaneously with an intradermal tuberculin test for additional identification of infected animals in farms unaffected by tuberculosis or when selecting animals for diagnostic slaughter. The diagnosis of tuberculosis during pathological examination is most often confirmed in animals that react simultaneously when examined in each of the samples.

Ocular tuberculinization is carried out twice with an interval of 5-6 days between administrations. Tuberculin in an amount of 3-5 drops is applied with a pipette or syringe without a needle to the conjunctiva of the lower eyelid or to the surface of the cornea with the lower eyelid retracted.

Animals that responded to the first injection of tuberculin are not given the drug again.

The results of the ophthalmic test are recorded after 6,9,12, and 24 hours after the first and 3,6,9 and 12 hours after repeated administration of tuberculin. Positive reaction characterized by the formation of mucopurulent or purulent secretion accumulating in the conjunctival sac or flowing in the form of a cord from the inner corner of the eye, hyperemia and swelling of the conjunctiva. When taking into account the reaction, it is necessary to retract the lower eyelid and inspect the conjunctival sac, since the reaction may be limited to the short-term formation of purulent secretion in the form of grains.

Short-term hyperemia and lacrimation with the formation of a small amount of mucous secretion, as well as the absence of any changes, are assessed as a negative reaction.

If, during routine tuberculinization in a prosperous farm, animals that react to tuberculin are identified for the first time, then in order to clarify the diagnosis, under the supervision of specialists from the state veterinary network, a commission diagnostic slaughter of 3-5 animals with the most pronounced reactions to tuberculin is carried out and internal organs and lymph nodes are examined. If detected in at least one of the killed animals pathological changes, typical for tuberculosis, the diagnosis is considered established.

If changes in organs and tissues characteristic of tuberculosis are not found in killed animals, material is taken for bacteriological examination with a bioassay. When mycobacterium tuberculosis of bovine or human species is isolated from material from killed animals or with a positive bioassay, the diagnosis is also considered established;

Immunity and specific prevention.

The emergence and development of the tuberculosis process is accompanied by irritation of the central nervous system. This causes an increase in the body's specific sensitivity to tuberculosis bacteria and their toxins. Increased sensitivity, or allergy, is detected several days or weeks after bacteria enter the body and marks not only the emergence of an infectious process, but also the beginning of the formation of a certain degree of non-sterile immunity.
In tuberculosis, phagocytosis is rarely complete; bacteria multiply in neutrophils and macrophages. Agglutinins, precipitins and complement-fixing antibodies also play a minor role in immunity. In the process of evolution, the body has developed the ability to isolate (immine) the pathogen in granulomas-tubercules. The degree of this ability, depending on many factors, including the virulence of the pathogen, can be different, and this determines the outcome of the disease. Infectious (non-sterile immunity) continues as long as tuberculosis bacteria are in the body; with their release or death, immunity also ceases.

For specific prevention of tuberculosis in medical practice, the BCG vaccine, made by Calmette and Guerin (1924) from a culture of bovine mycobacteria, is widely used.

Specific prevention of tuberculosis with the BCG vaccine is possible, but in most countries farm animals are not vaccinated against tuberculosis.

Prevention. Prevention and control measures against tuberculosis are carried out in accordance with current sanitary (SP 3.1 093-96) and veterinary rules (VP ​​13.3 1325-96).

Animal owners, farm managers, regardless of their form of ownership, peasant farm owners and others are obliged to:

• if you have or purchase animals, register them at a veterinary institution, obtain a registration number in the form of a tag and monitor its safety;
• purchase, sale, slaughter, pasture, placement on pastures and all other movements and regroupings of animals, sale of livestock products must be carried out only with the knowledge and permission of the state veterinary service authorities;
• equip the necessary veterinary and sanitary facilities;
• take precautions when preparing feed to prevent infection;
• quarantine newly arrived animals for 30 days for veterinary research and treatment;
• promptly inform the veterinary service about all cases of illness in animals with suspected tuberculosis (loss of fatness, signs of pneumonia, enlarged superficial lymph nodes);
• produce upon request veterinary specialists all necessary information about purchased animals and create conditions for their inspection, research and processing;
• comply with zoohygienic and veterinary requirements when transporting, keeping and feeding animals, and constructing livestock facilities;
• carry out timely delivery of sick animals or complete elimination of all unfavorable livestock as directed by veterinary specialists;
• ensure the implementation of restrictive, organizational, economic, special and sanitary measures provided for in these rules to prevent tuberculosis in animals, as well as to eliminate an epizootic outbreak in the event of its occurrence, with the allocation of the necessary material, technical and financial resources.

Treatment. Animals with tuberculosis are sent for slaughter. In herds, on farms, in populated areas where the disease has already been established, animals that react to tuberculin are recognized as having tuberculosis and sent for slaughter within 2 weeks.

Characteristics of the disease

Tuberculosis is a contagious, infectious disease caused by Mycobacterium tuberculosis, diverse in manifestation and course, affecting various organs, most often the lungs, intestines, and lymph nodes. All types of farm animals, wild animals, birds and humans suffer from tuberculosis. The disease spreads enzootically.

Tuberculosis, as an anthroponotic disease, poses a great epizootological and epidemiological danger and causes enormous damage to the national economy of the country and human health. Therefore, veterinary science and practice, together with medicine, must constantly pay attention to increased attention this problem.

Mycobacterium tuberculosis of the bovine species is most pathogenic for cattle, although all mammals and humans are susceptible to them. In addition to humans, pigs, cats, dogs, large and small livestock are susceptible to the pathogen of human tuberculosis.

M. avium is the causative agent of tuberculosis in domestic and wild birds. It can cause pathological changes in pigs, and in cattle it causes short-term sensitization to tuberculin.

The causative agent of tuberculosis is a strict aerobe. Optimal growing temperature: M. tuberculosis – 37-38 ºС, M. Bovis – 38-39 ºС, M. Avium – 39-41 ºС. The optimum pH of the environment is 6.8-7.4. In the presence of glycerol, which is a source of carbon, in the nutrient media, abundant growth of crops is observed. For the reproduction of bacteria, phosphorus, potassium, magnesium and sulfur are needed. Iron supplements stimulate growth.

They grow on liquid nutrient media forming a thick folded film; on dense media they form a whitish-yellow coating.

The pathogen contains esterase and lipase enzymes that break down fats and amino acids. Contains endotoxins-tuberculins (R. Koch 1890). They are stained bright red using the Ziehl-Neelsen method, and other microflora are stained blue.

To grow the causative agent of tuberculosis, glycerin MPA, MPB, potatoes, egg and synthetic media are used. Cultures grow slowly: human mycobacteria - 20-30 days, bovine mycobacteria - 20-60, avian - 11-15 days. If there is no growth, it is recommended to keep the crops in a thermostat for 3 months (Fig. 3.)

The species of the causative agent of tuberculosis is determined by the characteristics of their growth on artificial nutrient media and by performing a bioassay on guinea pigs, rabbits and chickens.

Many species of domestic animals are susceptible to tuberculosis, including game animals and birds (more than 55 species of mammals and about 25 species of birds). This disease is most often recorded in cattle, pigs, minks and chickens; less often - in goats, dogs, ducks and geese; very rarely - in sheep, horses and cats. Monkeys are highly susceptible to tuberculosis. Among wild ungulates, deer are more often affected. Humans also suffer from tuberculosis.

The patterns and features of the epizootic process in areas permanently unfavorable for tuberculosis are associated with two of its universal characteristics: continuity and unevenness. The first is determined by the interconnectedness of the sources of the pathogen with the susceptible organism through the mechanism of transmission of the pathogen, the second is a reflection of internal influences on its individual links.

The source of the infectious agent is animals suffering from tuberculosis, from whose bodies the pathogen is excreted in milk, feces, nasal discharge, and sometimes with sperm. When cows are infected with any type of tuberculosis pathogen, mycobacteria are always excreted in the milk.

Transmission factors for the causative agent of tuberculosis can be feed, water, pastures, bedding, manure, etc. contaminated with secretions of sick animals. Young animals are mainly infected through milk and skim milk obtained from sick animals. Intrauterine infection of calves is possible. Animals can become infected with the human species through contact with people with tuberculosis.

Open carriers of the causative agent of tuberculosis pose a great epizootological danger, since in many cases they are not detected by accepted diagnostic reactions, and when transported to a healthy herd they become sources of infectious agents and cause an epizootic process.

The route of infection is predominantly nutritional, but aerogenic cannot be ruled out, especially when patients are kept together with healthy people in closed, poorly ventilated, damp rooms.

Tuberculosis spreads significantly slowly among animals. This is explained by the length of the incubation period of the disease (up to 45 days). Inadequate feeding, unsatisfactory living conditions (overcrowding, dampness) and others unfavorable factors reduce the overall resistance of the animal body and contribute to the rapid spread of the disease. There is no definite seasonality in the manifestation of the epizootic process in tuberculosis. However, in cattle it is more often recorded during the stall period.

Tuberculosis usually occurs chronically, and often without visible signs. A positive reaction to tuberculin in animals occurs on the 14th to 40th day after their infection (incubation period); most animals with tuberculosis in appearance and general condition, especially at the onset of the disease, are no different from healthy ones. Sick animals are identified mainly by allergic testing; tuberculosis lesions are usually detected only during post-mortem examination of the organs. As a result of systematic planned examinations of livestock (tuberculinization), it is possible to identify the disease in the initial stage. The appearance of clinically pronounced forms of tuberculosis indicates a long course of the disease.

Based on the location of the pathological process, pulmonary and intestinal forms of tuberculosis are distinguished; There are also lesions of the udder and serous integument (pearl), the genital form and generalized tuberculosis.

There are several stages in the development of tuberculosis:

1) primary tuberculosis, observed in the forms:

a) primary complex (complete, incomplete, complex)

b) early generalization;

2) secondary tuberculosis, observed in the forms:

a) late generalization

b) tuberculosis of individual organs.

Primary tuberculosis is the stage of tuberculosis that occurs after the initial infection with tuberculosis. Pathological primary tuberculosis is manifested by the primary complex (PC).

A primary lesion that occurs simultaneously in an organ and its regional lymph nodes is called a complete primary complex; if only lymph nodes are affected, it is called an incomplete complex. The primary complex, localized in several body systems (for example, respiratory and digestive), is called complex. Early generalization is the spread to early stage pathological process in the body.

There are two points of view on the development of secondary (post-primary) tuberculosis:

1) this tuberculosis is a direct continuation of the primary one and develops from it;

2) secondary tuberculosis occurs after the primary tuberculosis foci have been cured and is the result of reinfection.

The spread of the process in the presence of a healed primary complex is called late generalization.

However, much more often secondary tuberculosis manifests itself as isolated organ tuberculosis. This form is expressed local defeat with resistance to tuberculosis of the body as a whole.

Conventionally, it is customary to distinguish between open (active) tuberculosis, when the causative agent of the disease is released into the external environment with milk, feces, sputum when coughing, and closed (latent) in the presence of encapsulated foci without the release of the pathogen into the external environment. When the intestines, mammary gland, or uterus are affected, the process is always considered open.

A pathological examination of the organs showed that the development of the tuberculosis process begins with damage to the lymph nodes. In this case, the mediastinal and retropharyngeal and, to a lesser extent, the submandibular, portal and mesenteric lymph nodes, as well as the lungs and liver are primarily affected.

In cattle, tuberculosis most often affects the lungs. If they are severely affected, they experience a slight increase in body temperature, a rare but severe cough; with a prolonged course of the disease, the cough becomes weak, silent, but painful. Expectoration is almost not observed in livestock; the bronchial mucus released during coughing is swallowed or excreted through the nose. In sick animals, shortness of breath, decreased appetite, fatness and productivity are noted. Visible mucous membranes are anemic. Auscultation of the lungs reveals wheezing, and percussion reveals areas of dullness. Intestinal damage, which is accompanied by diarrhea, is accompanied by rapid exhaustion and increasing weakness of the sick animal.

Damage to the mammary gland is characterized by an enlargement of the suprauterine lymph nodes, which become dense, lumpy, and inactive. In the affected lobes of the udder, compacted painless foci are felt; with significant damage, the configuration of the affected lobe changes. When milking, watery milk mixed with blood or curdled mass is released. When the genital organs are affected, cows experience increased estrus and barrenness, and bulls experience orchitis.

In generalized tuberculosis, superficially located lymph nodes (submandibular, prescapular, knee fold, suprauterine) are inactive.

Diagnosis

In view of the fact that tuberculosis infection, as a rule, occurs chronically and latently in animals, the most important measures in the system are the timely identification of infected animals and their removal from the herd as possible sources of the infectious agent. For many years, the main and very reliable diagnostic method was the intradermal allergy test.

Currently, veterinary specialists firmly know that the primary diagnosis of tuberculosis in a previously prosperous farm can only be made using a comprehensive method.

The complex of diagnostic studies for tuberculosis should include epizootological, clinical, pathological, and laboratory diagnostic methods, as well as an allergic intradermal tuberculin test.

Duration of examination: microscopic - on the day of receipt of the material, allergic - up to 3 days, bacteriological - up to 3 months, biological - up to 3 months.

Epizootological diagnostic method.

If an animal is suspected of having tuberculosis, an epizootological study is first carried out. The main goal of this study is to identify the possibility of introducing the pathogen into the farm, the nature of the epizootological process and the degree of spread of the disease among animals.

During an epizootological study, it is necessary to find out the epizootic situation of the farm in the past.

When carrying out all this work, we must not forget about animals that are in the personal use of workers and employees, since often these animals come into contact while grazing on the same pastures and using a common reservoir.

Clinical diagnostic method.

Severe clinical forms of tuberculosis, characterized by typical damage to the lungs, udder, and intestines, are now extremely rare. Despite this, the clinical method for diagnosing tuberculosis is very important.

In cattle, the lungs or intestines are more often affected, less often the udder, and in bulls there may be orchitis. With generalized tuberculosis, animals lose a lot of weight, and the affected lymph nodes are enlarged. With tuberculosis of the udder, compacted areas on it and enlargement of the supra-udder lymph nodes are noted.

The diagnosis of tuberculosis is considered established:

When a culture of the causative agent of tuberculosis is isolated or when a positive result of a biological test is obtained.

In cattle, in addition, the diagnosis is also considered established when pathological changes typical of tuberculosis are detected in the organs or tissues of animals.

Pathoanatomical diagnostic method.

At the first stage, they try to detect macroscopic (visible) changes. Research starts from the head. The tonsils, submandibular and retropharyngeal middle lymph nodes are carefully examined. Then the lymph nodes of the lungs are opened: bronchial, mediastinal. After this, the lung tissue is examined.

When examining the abdominal organs, pay special attention to the mesenteric lymph nodes, liver, spleen, kidneys, and when opening the udder, to the external inguinal lymph node. They examine the carcass, paying attention to the condition of the pleura, costal lymph nodes, and deep inguinal lymph node.

At the end of the study, material is taken for bacteriological and histological studies. For the induction and isolation of Mycobacterium tuberculosis from pathological materials, a method is proposed for cultivating mycobacteria on paraffin disks in a liquid nutrient medium (such as Soton's medium), in combination with conventional microscopy, from pathological materials not previously cleared of banal microflora.

Laboratory diagnostic methods.

The material is sent to the laboratory in cases where, in a farm free of tuberculosis, during the diagnostic slaughter of animals that reacted to tuberculin, pathological anatomical changes specific to tuberculosis are not detected, or they are not clearly expressed.

Research is carried out using microscopic, cultural and biological methods.

Allergic tuberculin test.

Dry purified tuberculin (protein-purified derivative-PPD) is used. Dry purified tuberculin PPD was proposed by M. A. Linnikova for medical practice. In veterinary medicine, standardized dry purified tuberculin for mammals is used, which contains 10,000 tuberculin units (TE-0.2 mg of the drug dissolved in 0.2 ml of solvent) in a diagnostic dose. The diagnostic dose of alttuberculin in the same volume is 18,000 TU.

Serological diagnosis.

Currently, tuberculosis antigens have been obtained and tested in different versions, which are used in a wide variety of serological diagnostic reactions. RSK is approved as an auxiliary method for diagnosing tuberculosis.

Sampling for tuberculosis testing

When taking samples for tuberculosis testing, the purpose of the study and the nature of the object from which the samples are taken are taken into account. If it is necessary to confirm the presence of tuberculosis with positive tuberculin reactions and negative autopsy results, they resort to examining material taken from both killed and living animals. From the latter, samples are taken multiple times at different intervals. Samples for research from living animals are milk, sputum, urine, feces, vaginal discharge.

A milk sample is taken from all four lobes of the udder. First, the udder is washed with warm water and soap, dried with a sterile cloth, and then the nipples are wiped with 70º alcohol. Hands are treated in the same order when taking samples. The first streams of milk are milked separately, and then a sample is taken in a sterile container from the first and last portions of the milk yield. At least 25 ml of milk is taken from each lobe of the udder. The entire sample is centrifuged at 3000 rpm for 20-30 minutes. The precipitate is treated with 6% sulfuric acid solutions, washed with saline, and centrifuged. Examine the sediment and cream layer.

A sputum sample is collected using sterile gauze pads during a cough; if necessary, a cough is induced artificially (mucus can be collected with a spoon from the nasal mucosa). Pour an equal volume of a 10% solution of trisodium phosphate, mix well and place in a thermostat for 24 hours. Then centrifuge at 3000 rpm for 10-15 minutes. Examine the sediment.

A urine sample is taken with a sterile catheter in the amount of 150-200 ml. from the bladder or during urination.

A fecal sample is taken from the rectum in an amount of 30-50 g and placed in a sterile glass jar with a lid.

A sample of discharge from the vagina and other cavities is collected with a sterile spoon in an amount of 3-5 ml.

After forced slaughter or death of an animal, pieces of altered organs and tissues with fresh, not yet encapsulated and non-calcified lesions are sent to the laboratory. If there are no visible changes in the organs of animals that react to tuberculin, the retropharyngeal, submandibular, bronchial, mediastinal, inguinal, prescapular lymph nodes, as well as pieces of the middle lobes of the lung, are sent to the laboratory for bacteriological examination. The material can be preserved with a 30% aqueous solution of glycerin.

Immunity and means of specific prevention.

In tuberculosis, it is non-sterile, remaining as long as the mycobacteria are in the body. Phagocytosis is incomplete, and phagocytosed mycobacteria do not die. The body produces agglutinins and complement-fixing antibodies, but their role in immunity is insignificant. Protection is mainly determined by the body’s ability to stop the pathological process and limit the pathogen in granulomas-tubercules.

Infected animals develop a state of relative immunity and exogenous infection. Atypical mycobacteria also have immunizing properties to a certain extent. Cellular immunity, non-sterile, is preserved for the period that mycobacteria are in the body. In some areas of the country, vaccine and chemoprophylaxis of calf tuberculosis is used using BCG and isoniazid vaccines.

The role of living pathogens in the formation of immunity in tuberculosis is confirmed by the experiments of R. Koch on re-infection of sick guinea pigs. With primary subcutaneous infection, a nodule forms at the injection site after 10-15 days, and then a non-healing ulcer. Along with this, inflammation of the surrounding lymph nodes is observed. After repeated infection, after 4-6 weeks, an edematous-inflammatory focus appears at the injection site, the skin becomes necrotic, sloughs off and an ulcer forms, which heals quickly. In this case, the lymph nodes are not involved in the process. This experience, called the Koch phenomenon, shows that secondary introduced mycobacterium tuberculosis occurs in the body with partial immunity, as a result of which reactive inflammation, which quickly develops at the site of infection, localizes and removes the secondary affect, thus eliminating the reaction. In this case, the increased sensitivity of the body prevents the spread of mycobacterium tuberculosis and helps remove them from the body.

Prevention and control measures.

In order to prevent animals from contracting tuberculosis, farm managers, livestock owners and veterinary specialists are obliged to:

Do not allow the introduction of animals from other disadvantaged farms and settlements, as well as the movement of animals within the farm without the permission of veterinary specialists;

Examine all animals entering the farm during the 30-day quarantine period for tuberculosis allergic method. Animals are introduced into the general herd only when each of them receives negative test results.

If the study reveals responsive animals, measures are taken to establish a diagnosis, and if tuberculosis is established, all livestock in this group are slaughtered.

Organize on every farm strict adherence sanitary rules, implement a set of preventive measures that help increase the natural resistance of the animal body. Equip the necessary veterinary and sanitary facilities.

Do not allow strangers to visit livestock farms, barnyards. Avoid contact of animals with livestock of households (farms) unaffected by tuberculosis, populated areas on pastures, in livestock watering areas, etc., strictly follow “ Veterinary regulations on the prevention of infection of pastures, water sources and routes for driving (transporting) livestock with pathogens of tuberculosis, as well as their disinfection.”

When selling or exporting animals to other farms for inter-farm exchange and breeding purposes, it is allowed to select from farms free from tuberculosis for at least 4 years.

State veterinary inspectors of the districts are obliged to ensure that the epizootic state of the animal population on each farm is checked in relation to tuberculosis.

In some farms, recovery from tuberculosis is carried out using the BCG vaccine (with the permission of the veterinary department).

The effectiveness of the BCG vaccine:

1. The use of the BCG vaccine promotes the formation of immunity.

2. Annual BCG vaccination of livestock makes it possible to identify animals with active forms of tuberculosis by the manifestation of hyperergic reactions to the vaccine.

Negative side: at the age of 16-18 months (i.e. during the selection period of heifers), many revaccinated calves (12 months after revaccination) react to tuberculin. Unfortunately, there are no tests to distinguish post-vaccination allergies from infections.

The most intense immunity (100%) was obtained with a three-time administration of the BCG vaccine (at the age of 10-15 days, 12 and 18 months after the first calving), which is confirmed by laboratory methods for studying material from animals.

For disinfection livestock premises a composite mixture was proposed - an alkaline solution of sodium phenolate. Both components of this mixture (aqueous sodium phenolate solution and spent alkali solution) are waste from chemical production. During a laboratory study of this drug, it was found that it has a pronounced bacteriostatic effect on Mycobacterium tuberculosis.

Conducting research using the methodology developed by the staff of the veterinary department showed the lack of preparation of practical veterinary services for qualified diagnosis, prevention and measures to combat infectious diseases of animals. All this indicates the need to transition to active forms of training for veterinary specialists. One of these methods is business games (questionnaire method, on cards, role-playing game).

According to the sanitary and veterinary rules of 1996, in order to determine the well-being of the herd, it is necessary to first determine the degree of ill-being of the cattle herds, taking into account the prevalence of the disease: more or less limited - when a double tuberculin test is detected in up to 15% of the animals present in the herd (on the farm) ; significant – when more than 15% of sick animals are detected.

The improvement of herds of cattle affected by tuberculosis is carried out in the following ways:

a) systematic diagnostic studies with isolation of sick animals or entire disadvantaged groups and their subsequent slaughter;

b) one-time complete replacement of the population of a dysfunctional herd (farm) with healthy animals.

In both cases, it is mandatory to implement a set of organizational and sanitary measures provided for by these Rules.

Lump sum method complete replacement livestock is used when tuberculosis is first established in a district, region, republic, and when there is a significant prevalence of the disease in the herd (incidence is more than 15% of the population).

In this case, after imposing restrictions:

Stop allergic testing of livestock for tuberculosis;

Cows and heifers are not inseminated;

All milk obtained is pasteurized at 85 ºС for 30 minutes. or at 90 ºС for 5 minutes, after which it is used for feeding fattening calves or sent to a milk processing plant;

Within 6 months, the entire population of the dysfunctional herd, together with the young animals, is handed over for slaughter. First of all, fattening livestock, unproductive cows, oxen and young animals are sent to the meat processing plant;

After clearing the premises of livestock, they are disinfected with a 3% alkaline solution of formaldehyde;

In all vacated cowsheds, calf barns, maternity wards, and workshops, the floors, passages and walls are cleared of manure and feed residues, and conveyors for mechanical removal of manure are dismantled;

Wooden floors are removed. Suitable for reuse After thorough cleaning and washing, the boards are disinfected for 24 hours in baths with a 3% solution of formaldehyde and caustic soda. Unusable boards are burned;

They remove 15-20 cm of underground soil and take it outside the farm for biothermal neutralization, and new soil is brought to this place;

Clear the farm area and walking areas of garbage and manure;

All manure is transported outside the farm to a specially designated place, stored in piles 3 m wide and 2 m high, covered with earth and fenced; This manure is used no earlier than 2 years after being placed in piles;

Livestock buildings are being renovated, floors are being laid, manure conveyors are being installed;

All unusable work clothes, shoes, and low-value equipment are burned;

After completion of veterinary and sanitary measures, final disinfection of all premises on the farm territory and laboratory testing of the quality of disinfection, restrictions are lifted from the unfavorable farm.

If less than 15% of the herd is infected with tuberculosis, recovery can be carried out by systematic diagnostic studies with the slaughter of sick animals:

All animals from 2 months of age are examined every 45-60 days with an allergic intradermal tuberculin test. At the same time, other species of animals (including dogs and cats) on the farm are tested for tuberculosis. Animals that react to tuberculin are recognized as sick, marked with the letter “T”, isolated and sent for slaughter within 15 days. Dogs and cats that react to tuberculin are killed.

At the same time, the requirement that contacts between sick and healthy animals be inaccessible is in some cases simply difficult to fulfill. Thus, when improving health by this method, valuable cattle most often fall ill in the first year after being introduced into the main herd due to complete absence he has immunity. Therefore, herd repairs must be carried out with healthy heifers from the same herd.

If two consecutive negative test results are obtained throughout the herd, the animals are put on a 6-month follow-up observation, during which two studies are carried out with an interval of 3 months. Upon receiving negative results and carrying out a set of veterinary and sanitary measures, the farm (herd) is declared free from tuberculosis.

In herds healed by this method, proceed as follows:

Calves born from sick cows are slaughtered along with their mothers;

Heifers born from non-responding cows of the healing herd (before it is placed under control supervision) are kept in an isolated group, fed for fattening and then slaughtered;

Young animals obtained during the control observation period are raised under conditions of isolation, and after restrictions on the farm are lifted, they are used in the usual manner.

Before restrictions are lifted, a set of veterinary and sanitary measures are carried out.

It is necessary to raise young cattle in isolation according to the following scheme: feeding them up to 7-10 days with colostrum and mother's milk, and then with milk replacer and dry skim milk or milk and skim milk, pasteurized at 85 ºС for 30 minutes. The technology for raising animals is organized according to the “empty – occupied” principle. After being cleared of animals, the room or section is cleaned, washed, disinfected and refilled with newborn calves no less than 4 days later.

The work of many scientists has established that mycobacterium tuberculosis inside livestock buildings is found on the surface of floors, walls, pillars, and equipment of other objects. The number of mycobacterial cultures isolated is directly dependent on the epizootic state of farms. In this regard, quality control of disinfection should be considered as one of the most important methods of combating tuberculosis.



Tuberculosis (Tuberculosis) is an infectious, predominantly chronic disease of many species of agricultural and wild animals, including fur-bearing animals and poultry, characterized by the formation in various organs of specific nodules - tubercles, prone to cheesy disintegration.

Historical background

Tuberculosis has been known since ancient times. Clinical signs of the disease in humans were described by Hippocrates in the 4th century. BC e. The term “tuberculosis” was first used by the French physician Lennec (1819), and the contagiousness of the disease was proven by J. A. Villemin (1865). The causative agent of tuberculosis was discovered by R. Koch (1882), and he also produced tuberculin in 1890. Russian researcher X. I. Gelman proposed tuberculin in 1888, but published the work only in 1892. In 1924, Calmette and Guerin produced the BCG vaccine to prevent tuberculosis in humans.

Animal tuberculosis is registered in many countries around the world. In most European countries it has been practically eliminated.

Great contribution to the study of tuberculosis and development health activities contributed by S. N. Vyshelessky, P. P. Vishnevsky, M. K. Yuskovets, I. V. Poddubsky, V. I. Rotov, A. V. Akulov, N. A. Naletov and others.

The causative agent is a microorganism of the genus Mycobacterium. There are three main types of tuberculosis pathogens:

1) M. tuberculosis (human species);

2) M, bovis (bovine species);

3) M. avium (avian).

In terms of morphology and cultural properties, they are largely similar to each other; these are thin, straight, often slightly curved rods 0.8-5.5 microns long, located singly or in groups in smears. Branched, filamentous and coccus-like forms of the microbe are also found. The microbial cell membrane contains fatty wax-like substances, and granularity is noted in the protoplasm. Mycobacteria are strict aerobes, nonmotile, do not form spores or capsules, acid-alcohol-resistant; are stained by the Ziehl-Neelsen method in bright red, and other microflora are stained blue (color table I, L).

To grow the causative agent of tuberculosis, glycerin MPA, MPb, potatoes, egg and synthetic media are used. Cultures of mycobacteria of the human species grow slowly - 20-30 days, bovine species - 20-60, avian - 11 - 15 days. If there is no growth, it is recommended to keep the crops in a thermostat for 3 months. The pathogenicity of individual types of the causative agent of tuberculosis for different species of animals and humans is not the same. So, people are most sensitive to the pathogen of the human species, pigs, cats, dogs, cattle, fur-bearing animals are also susceptible, but birds do not get sick! (except parrots). All farm and wild animals, including fur-bearing animals, as well as humans, are sensitive to the bovine pathogen, but birds are immune. Birds and pigs are sensitive to the avian pathogen, and very rarely other mammals - animals and humans - become infected with it. Animals infected with avian mycobacteria may respond to mammalian tuberculin.

The species of the causative agent of tuberculosis is determined by the characteristics of their growth on artificial nutrient media and by performing a bioassay on guinea pigs, rabbits and chickens.

Differentiation of the species of the causative agent of tuberculosis in a bioassay.

Sustainability

Mycobacteria are very resistant to various environmental factors and chemicals. This property is explained by the presence of fatty wax substances in the microbial cell.

The causative agent of tuberculosis remains viable in manure for 7 months, in dried cow feces for up to a year, in soil for more than two years, in river water for up to 2 months; in meat, frozen and stored in the refrigerator - up to a year, in salted meat - 45-60 days, in butter - up to 45, in cheese - 45-100, in milk - up to 10 days. Pasture areas where animals with tuberculosis were grazed remain infected throughout the entire summer period (V.N. Kislenko, 1972).

Heating milk to 70°C kills the tuberculosis pathogen in 10 minutes, and boiling it in 3-5 minutes. The best disinfectants are an alkaline 3% solution of formaldehyde (exposure 1 hour), a suspension of bleach containing 5% active chlorine, a 10% solution of iodine monochloride and a 20% suspension of freshly slaked lime, applied by three times whitewashing with an interval of 1 hour

In addition to the pathogenic mycobacteria of the three named types of the causative agent of tuberculosis (pathogenic mycobacteria), the genus Mycobacterium contains a large group of atypical mycobacteria. Based on morphological characteristics, they are difficult to distinguish from the causative agent of tuberculosis; they are often represented by coarser, thicker, non-granular rods of different lengths. Atypical mycobacteria are widespread in nature, and many of them are saprophytes. Once in the body of animals, atypical mycobacteria are able to multiply in it, and create short-term sensitization of the body to tuberculin for mammals.

Epizootological data

Many species of domestic and wild animals are susceptible to tuberculosis, including game animals and birds (more than 55 species of mammals and about 25 species of birds). This disease is most often reported in cattle, pigs, minks and chickens; less often - in goats, dogs, ducks and geese; very rarely - in sheep, horses and cats. Monkeys are highly susceptible to tuberculosis. Among wild ungulates, deer are more often affected. Humans also suffer from tuberculosis.

The source of the infectious agent is animals with tuberculosis, from whose bodies the pathogen is excreted in milk, feces, nasal discharge, and sometimes with sperm. When cows are infected with any type of tuberculosis pathogen, mycobacteria are always excreted in the milk.

Transmission factors for the causative agent of tuberculosis can be feed, water, pastures, bedding, manure, etc., contaminated with secretions of sick animals. Young animals are mainly infected through milk and skim milk obtained from sick animals. Intrauterine infection of calves is possible. Animals can become infected with the human species through contact with people with tuberculosis.

The route of infection is predominantly nutritional, but aerogenic cannot be ruled out, especially when patients are kept together with healthy people in closed, poorly ventilated, damp rooms. Pigs often become ill when fed raw kitchen waste, as well as through contact with birds sick with tuberculosis. Birds become infected through nutritional means, but transovarial transmission of tuberculosis has also been established in chickens. Sick birds lay infected eggs. When infected eggs are incubated, many embryos die, and some of the hatched chickens become a source of the tuberculosis pathogen. Wild birds can be carriers of all three types of tuberculosis pathogen.

Tuberculosis spreads relatively slowly among animals. This is explained by the length of the incubation period of the disease (up to 45 days). Inadequate feeding, unsatisfactory living conditions (overcrowding, dampness) and other unfavorable factors reduce the overall resistance of the animal's body and contribute to the rapid spread of the disease. There is no definite seasonality in the manifestation of the epizootic process in tuberculosis. However, in cattle it is more often recorded during the stall period.

Pathogenesis

The causative agent of tuberculosis, having entered the body through the digestive tract with food or inhaled air, penetrates the lungs or other organs. At the site of its localization, an inflammatory process develops, manifested by cellular proliferation and exudation; There is an accumulation of multinucleated giant and epithelioid cells surrounded by a dense layer of lymphoid cells. The exudate accumulated between the cells coagulates, forming a network of fibrin, and an avascular tuberculous nodule is formed - tubercle. It initially has a grayish color and a round shape; its size is from the head of a pin to the size of a lentil grain. Soon the nodule is surrounded by a connective tissue capsule. The tissue inside the encapsulated nodule, due to the lack of influx of nutrients and under the influence of pathogen toxins, dies and turns into a dry crumbly mass resembling cottage cheese (caseosis).

If a primary tuberculous nodule develops only at the site of entry of the pathogen (lungs, intestines), then such a fresh, isolated focus is called the primary effect. From there, the pathogen usually travels through the lymph flow to the regional lymph node, where pathological changes also develop. Simultaneous damage to an organ and a regional lymph node is called a complete primary complex. If the process develops only in the regional lymph node, then it is called an incomplete primary complex.

In a benign course of the disease, the primary focus undergoes calcification, a dense connective tissue capsule forms around it, and further development of the infectious process stops. In an organism with reduced resistance, the process of encapsulation of the pathogen in primary focus poorly expressed. Due to insufficient regeneration of connective tissue, the walls of the tuberculous nodule melt, and mycobacteria enter healthy tissue, which leads to the formation of many small, translucent nodules ( miliary tuberculosis). Small tubercles can merge with each other, forming large tuberculosis foci.

Mycobacteria from tuberculosis foci can enter the blood, which leads to the generalization of the process and the development of tuberculosis foci of different sizes in various organs (liver, spleen, kidneys, etc.). With a long course of the disease, large tuberculosis foci and cavities can form in the lungs, sometimes reaching the size of a fist. A dense connective tissue capsule grows around them. Tuberculous cavities can communicate with the lumen of the bronchi. In such cases, their contents liquefy and are released when coughing with sputum.

In the generalized form of tuberculosis and extensive lesions in the lungs, gas exchange is disrupted, srithropoiesis is inhibited, anemia is observed, productivity decreases, exhaustion and death of the animal occur.

Course and symptoms

Tuberculosis usually occurs chronically, and often without clearly visible signs. A positive reaction to tuberculin in animals occurs on the 14-40th day after infection (incubation period). Most animals with tuberculosis are no different from healthy ones in appearance and general condition, especially at the onset of the disease. Sick animals are identified mainly by allergic and serological testing; tuberculosis lesions are usually detected only during post-mortem examination of organs. As a result of systematic planned examinations of livestock (tuberculinization), it is possible to identify the disease in the initial stage. The appearance of clinically pronounced forms of tuberculosis indicates a long course of the disease.

Based on the location of the pathological process, pulmonary and intestinal forms of tuberculosis are distinguished; There are also lesions of the udder and serous integument (pearl oyster), the genital form and generalized tuberculosis.

Conventionally, it is customary to distinguish between open (active) tuberculosis, when the causative agent of the disease is released into the external environment with milk, feces, sputum when coughing, and closed (latent) in the presence of encapsulated foci without the release of the pathogen into the external environment. When the intestines, mammary gland, or uterus are affected, the process is always considered open. In cattle, tuberculosis most often affects the lungs. If they are severely affected, they experience a slight increase in body temperature, a rare but severe cough; with a prolonged course of the disease, the cough becomes weak, silent, but painful. Expectoration is almost not observed in livestock; the bronchial mucus released during coughing is swallowed or excreted through the nose. In sick animals, shortness of breath, decreased appetite, fatness and productivity are noted.

Visible mucous membranes are anemic. Auscultation of the lungs reveals wheezing, and percussion reveals areas of dullness. Intestinal damage, which is accompanied by diarrhea, is accompanied by rapid exhaustion and increasing weakness of the sick animal.

Damage to the mammary gland is characterized by an enlargement of the suprauterine lymph nodes, which become dense, lumpy, and inactive. In the affected lobes of the udder, compacted painless foci are felt; with significant damage, the configuration of the affected lobe changes. When milking, watery milk mixed with blood or curdled mass is released. When the genital organs are affected, cows experience increased estrus and barrenness, and bulls experience orchitis.

In generalized tuberculosis, superficially located lymph nodes (submandibular, prescapular, knee fold, suprauterine) are inactive.

Tuberculosis in pigs is asymptomatic. Sometimes an increase in the submandibular and retropharyngeal lymph nodes is observed. Abscesses may appear in the affected nodes, after opening which a purulent-curdled mass is released. With extensive lung damage, coughing, vomiting, and difficulty breathing occur. Sheep and goats suffer from tuberculosis rarely and asymptomatically. With a highly expressed process, clinical signs are similar to those in cattle.

Tuberculosis in birds is chronic, with unclear clinical signs. The generalized form is accompanied by lethargy, decreased egg production, exhaustion (atrophy pectoral muscles). When the intestines are damaged, diarrhea is observed; liver - icteric staining of the mucous membranes and skin. Lameness and tumor-like formations on the plantar surface of the extremities are sometimes noted.

Among fur-bearing animals (foxes, mink, nutria), young animals are more often affected by tuberculosis. Patients experience weakness and progressive exhaustion; in the pulmonary form, cough and shortness of breath. Damage to the intestines is accompanied by diarrhea, and the liver is accompanied by icteric staining of the mucous membranes. Foxes sometimes develop long-lasting ulcers on their skin.

Pathological changes. Characteristic of tuberculosis is the presence in various organs and tissues of the animal of specific nodules (tubercles) the size of a millet grain to a chicken egg or more. Tuberculous foci are surrounded by a connective tissue capsule, their contents resemble a dry, crumbly, curdled mass (caseous necrosis). With prolonged illness, tuberculous nodules may become calcified.

In ruminants, tuberculosis lesions are most often found in the lungs and lymph nodes of the chest cavity. In the lungs, dense, reddish-grayish lesions are found; on section they are shiny, sebaceous (no necrosis), often with caseosis in the center; sometimes the lesions have purulent foci. Occasionally, caverns of various sizes are found (cows, goats). Lymph nodes are most often affected. They are enlarged, dense, lumpy, with caseous tissue disintegration in the center of the node.

When the serous integument is affected, multiple (pearl oyster) dense, shiny tuberculous nodules, reaching the size of a hazelnut, are found on the pleura and peritoneum. The intestinal form of tuberculosis is manifested by round ulcers with roller-shaped edges on the mucous membrane of the jejunum and ileum.

In cattle suffering from tuberculosis, the lymph nodes of the chest cavity are affected in 100% of cases, the lungs - in 99, the liver - in 8, the spleen - in 5, the udder - in 3, the intestines - in 1% of cases (P.I. Kokurichev, 1950) . In pigs, tuberculosis lesions are most often found in the lymph nodes of the mesentery and head and less often in the liver and other organs. In poultry they are localized mainly in the liver (90% of cases), spleen (70%), bones and intestines.

It is placed on the basis of an analysis of epizootic data, clinical signs and the results of allergic, serological (RSC with tuberculosis antigen), pathological, histological, bacteriological and biological studies. The clinical method for diagnosing tuberculosis is of limited value, since the clinical signs of the disease in animals are not typical enough, and at the onset of the disease they are not present at all.

The main method of intravital diagnosis of tuberculosis is an allergic study. For the study, tuberculin (allergen) is used - a sterile filtrate of killed cultures of the causative agent of tuberculosis. We prepare two types of tuberculin: dry purified tuberculin (PPD) for mammals and dry purified tuberculin SPD) for birds.

Dry purified tuberculin for mammals (protein purified derivative - PPD) consists of freeze-dried precipitated proteins from the cultural filtrate of the causative agent of bovine tuberculosis, grown on a synthetic nutrient medium. It is used for allergic diagnosis of tuberculosis in all mammals.

Dry purified tuberculin (DPT) for birds is similar in appearance and manufacturing technology to DPT for mammals. It is prepared from the cultural filtrate of the causative agent of avian tuberculosis and is used to diagnose tuberculosis in birds and pigs.

Tuberculinization methods. The main method of intravital diagnosis of tuberculosis in animals is an allergic study using a tuberculin test. In horses, an eye examination method (ophthalmic test) is used. In some cases, in cattle it is placed simultaneously with intradermal.

As an additional method for diagnosing tuberculosis in cattle, a simultaneous allergy test is used, which is carried out simultaneously with purified tuberculin for mammals and a purified complex allergen from atypical mycobacteria (CAM).

Animals are tested for tuberculosis from 2 months of age; breeding stock of cattle, buffaloes and camels - regardless of the period of pregnancy; sheep, goats, pigs, deer (deer), horses and donkeys - no earlier than a month after birth.

Place of injection.

With the intradermal method of research, tuberculin is administered to: cattle, buffalos, zebu, deer (deer) in the middle third of the neck; for stud bulls it is allowed to inject into the skin of the subcaudal fold, for pigs - in the area of ​​the outer surface auricle at a distance of 2 cm from its base (on one side of the auricle, PPD for mammals is introduced, on the other, PPD for birds). Pigs aged 2-6 months. It is better to inject tuberculin into the skin of the lumbar region, stepping back from the spine by 5-8 cm (tuberculin for mammals is injected on one side, for birds on the other), using a needle-free injector of the IBV-01 brand. For goats, sheep, dogs, monkeys, fur-bearing animals (except minks), tuberculin is injected into the area of ​​the inner thigh; minkam - intrapalpebrally into the upper eyelid; camels - in the skin abdominal wall in the groin area at the level of the ischial tuberosity; kuram—in the beard; for turkeys - in the submandibular earring; geese, ducks in the submandibular fold; pheasants, peacocks, parrots, pigeons, cranes, herons, storks, flamingos - in the area of ​​the outer surface of the lower leg, 1-2 cm above the ankle joint. The fur at the site of tuberculin injection is cut (feathers are plucked), the skin is treated with 70% alcohol.

For tuberculinization, special needles for intradermal injections with a double tube (MRTU No. 46-84-62) or needles No. 0612 and syringes with a slider with a capacity of 1-2 ml are used. Needleless injectors are widely used to administer tuberculin to animals.

During intradermal tuberculinization, tuberculin is administered once in a volume of 0.2 ml to all mammals, except monkeys and minks, as well as birds (to them in a dose of 0.1 ml).

Accounting and evaluation of the reaction. In cattle, buffaloes, zebu, camels and deer, they are carried out 72 hours after administration of the drug; for goats, sheep, pigs, dogs, monkeys, fur-bearing animals - after 48; in birds - after 30-36 hours. Local reaction for tuberculin administration can be assessed as positive or negative.

The reaction is considered positive if a diffuse (without clear boundaries with the surrounding tissue), doughy consistency, painful inflammatory swelling is formed at the site of tuberculin injection, accompanied by hyperemia and an increase in local temperature. In some animals, the reaction manifests itself in the form of a dense, painless, clearly contoured swelling (Fig. 1).

Cattle, buffalo, zebu, camels and deer are considered to respond to tuberculin if the above changes are present at the site of tuberculin injection and a thickening of the skin fold of 3 mm or more compared with the thickness of the fold of unchanged skin near the site of tuberculin injection.

Sire bulls tuberculinized in the subcaudal fold are considered to react when an inflammatory swelling forms at the site of tuberculin injection and the skin fold thickens by 2 mm or more.

In goats, sheep, pigs, dogs, monkeys, fur-bearing animals and birds, the reaction is considered positive when a swelling forms at the site of tuberculin injection, and in minks - when the eyelid is swollen.

Intradermal tuberculin test is a highly specific reaction to tuberculosis. However, it depends on the general immunoreactivity of the body and the sensitivity of animals to tuberculin. In animals of low fatness, old, deep-pregnant animals, as well as with a generalized tuberculosis process, the reaction to tuberculin may be weakly expressed or not manifested (anergy). It should also be taken into account that sometimes nonspecific (paraallergic) reactions to tuberculin are possible for mammals, due to sensitization of the body by avian mycobacteria, paratuberculosis pathogens and atypical mycobacteria, as well as other reasons. However, nonspecific reactions are unstable and disappear after a few months.

Rice. 1. Positive reaction to tuberculin: A - in a cow; B - pigs; B-birds

Differentiation of specific reactions from nonspecific reactions, if necessary, is carried out by a simultaneous test with avian tuberculin or a complex allergen from atypical mycobacteria (AM) and laboratory tests.

Tuberculinization by the eye method is carried out twice with an interval of 5-6 days. Tuberculin (3-5 drops) is applied with an eye dropper to the conjunctiva of the lower eyelid or to the cornea of ​​the eye (with a retracted lower eyelid). The reaction is taken into account after the first injection after 6, 9, 12 and 24 hours, after the second - after 3, 6, 9 and 12 hours. It is considered positive if a discharge of mucopurulent or purulent secretion occurs from the inner corner of the eye, accompanied by hyperemia and swelling conjunctiva.

Allergic testing for animal tuberculosis is allowed to be carried out only by veterinary specialists who have completed a special training course, are proficient in the technique of administering diagnostic drugs and have experience in assessing allergic reactions.

The diagnosis of tuberculosis is considered established: when a culture of the tuberculosis pathogen is isolated or when a positive result of a biological test is obtained. In cattle, in addition, the diagnosis is considered established when pathological changes typical of tuberculosis are detected in the organs or tissues of animals.

When positive results of allergic tests for tuberculosis are obtained, the diagnosis of the disease is carried out by slaughtering 3-5 animals with the most pronounced reactions to tuberculin and examining internal organs, bones and lymph nodes. In the absence of typical changes for tuberculosis, pieces of organs and lymph nodes are selected and sent to a veterinary laboratory for bacteriological examination.

All livestock of the herd, including previously reacting animals, are tested with a simultaneous test with tuberculin for mammals and the KAM allergen. In herds, on farms, in populated areas where the disease has already been established, animals that react to tuberculin are recognized as having tuberculosis.

Animals with tuberculosis are not treated and must be slaughtered. In disadvantaged fur farms, tubazid (isoniazid) is used to prevent tuberculosis in minks. The drug is given with food at a dose of 10 mg/kg of animal once a day for 75 days.

Immunity

In tuberculosis, it is non-sterile, remaining as long as the mycobacteria are in the body. Phagocytosis is incomplete, and phagocytosed mycobacteria do not die. The body produces agglutinins and complement-fixing antibodies, but their role in immunity is insignificant. Protection is mainly determined by the body’s ability to stop the pathological process and limit the pathogen in granulomas-tubercules. For specific prevention of tuberculosis in young cattle and minks, the dry BCG vaccine used in medicine is used. Clinically healthy animals are vaccinated with it.

Prevention and control measures

Measures to combat tuberculosis include the protection of healthy farms from the introduction of the infectious agent from the outside, systematic research in order to timely identify sick animals, the improvement of farms unfavorable for tuberculosis by slaughtering sick animals, the isolated rearing of healthy young animals and the implementation of a set of veterinary, sanitary and organizational and economic measures, aimed at protecting healthy livestock and destruction of the tuberculosis pathogen in the external environment; protecting people from tuberculosis infection.

In safe farms, all measures should be aimed at protecting the farm from the introduction of the pathogen. For this purpose, farms are staffed with healthy animals from farms that are free from tuberculosis. Newly received animals are examined for tuberculosis during a 30-day quarantine period. Feed is purchased only from farms that are free from tuberculosis. The skim milk supplied for feeding young animals is pasteurized, and the collected food waste is subjected to heat treatment. Persons with tuberculosis are not allowed to serve animals and keep poultry on the territory of livestock farms. Periodically, preventive disinfection of livestock premises is carried out, rodents and ticks are destroyed, and measures are taken to improve the feeding and maintenance of animals. In breeding farms it is strictly prohibited to use peat for animal feed and bedding.

In order to timely identify animals with tuberculosis and monitor the welfare of farms with regard to this disease, routine diagnostic tests of animals for tuberculosis are carried out annually. Cows, heifers and young cattle from 2 months of age, stud bulls, sows, boars, camels intended for sale for breeding purposes are examined.

Twice a year, cattle from breeding farms and farms supplying animals for stocking livestock complexes, milk and dairy products directly to children's and medical institutions, rest homes or to retail chains, as well as farms territorially bordering on disadvantaged areas, are tested for tuberculosis. tuberculosis points. Cattle belonging to citizens living on the territory of these farms are examined simultaneously with the farm livestock.

On breeding pig farms and in reproductive farms, sows are examined before weaning piglets, and boars - 2 times a year. In other farms, sows, boars and, if necessary, young animals from 2 months of age are examined once a year.

Monitoring the well-being of poultry and fur farms for tuberculosis is mainly carried out by inspection and pathological examination of dead and killed animals and birds, as well as by the allergic method. Horses, mules, donkeys and sheep are tested for tuberculosis on farms affected by this disease.

If tuberculosis occurs, the farm (farm) is declared unsafe, quarantine is established and a calendar plan of measures to eliminate the disease is drawn up.

In farms affected by tuberculosis in cattle, buffaloes and reacting animals, they are immediately isolated and slaughtered within 15 days. Young animals born from sick animals are fattened in isolated conditions and sent for slaughter. The remaining animals (not responding to tuberculin) of the unfavorable farm are tested for tuberculosis every 60 days until two negative results are obtained in a row for the group, after which two more control studies are carried out at an interval of 3 months. If negative results are obtained and there are no other indications for tuberculosis, this group of animals is considered healthy.

Calves born from animals from a dysfunctional farm that do not respond to tuberculin are raised in isolation and fed with the milk of healthy cows or neutralized milk (skim milk) of their mothers. At 2 months of age they are examined for tuberculosis using the intradermal method.

Calves that react positively to tuberculin are isolated and after fattening they are slaughtered. Non-responders are examined 2 more times with an interval of 60 days, then after 3 months. If a negative result is obtained for the entire group, they are considered healthy and used for production purposes only within the farm.

The improvement of farms with significant livestock affected by tuberculosis (more than 25% of animals) is carried out by slaughtering unfavorable livestock.

The success of the fight against tuberculosis largely depends on the activities of farm managers, who are called upon to provide the necessary assistance to veterinary specialists in conducting diagnostic studies, disinfection work, implement a set of preventive measures aimed at creating a high sanitary culture in livestock farming, increasing the natural resistance of the animal body, and equipping veterinary facilities - sanitary purposes, strictly comply with the requirements of the instructions for combating the disease.

In areas unfavorable for tuberculosis, it is recommended to create special groups (detachments) of veterinary specialists to carry out work on mass testing of animals for tuberculosis.

Under the terms of quarantine, it is prohibited to keep animals sick with tuberculosis in herds and in common livestock buildings, as well as the organization of any kind of temporary and permanent concentration points and isolation farms for keeping such animals on farms. In areas unfavorable for tuberculosis in cattle, it is not allowed to create off-farm complexes, farms and other enterprises for raising heifers. In all farms in such areas, on-farm farms (departments, teams, plots) should be organized for the isolated rearing of young animals. Livestock purchased by farms or consumer cooperation organizations from the population living in the territory of farms (settlements) unfavorable for tuberculosis are subject to immediate delivery for slaughter without fattening and fattening (in transit), regardless of weight standards.

It is prohibited to export undisinfected milk obtained from cows of a dysfunctional farm, farm, or herd in a populated area to milk processing plants, for sale in markets, for use in public catering networks, etc. Such milk is subject to primary processing directly on the affected farm (on the farm) for the entire time until the disease is completely eliminated and quarantine is lifted. At the same time, milk obtained from cows with clinical manifestations of tuberculosis is prohibited from being used for food purposes and as animal feed. It is disinfected by adding 5% formaldehyde or another disinfectant to the milk. Given this, sick cows should not be milked. Milk from cows that react to tuberculosis during testing is disinfected by processing it into raw ghee or by boiling.

Dairy products from non-responsive cows of a dysfunctional herd are disinfected at a temperature of 90 C for 5 minutes or at a temperature of 85 ° C for 30 minutes.

Dairy enterprises must release skim milk to farms only after it has been disinfected by pasteurization or heat treatment with live steam.

In specialized complexes, on farms for raising heifers (heifers), when a disease is detected in young animals of the technological (age) group in which patients are identified, all heifers of this group are slaughtered within 30 days, the rest of the animal population of the complex, farm - within 6 months (no more). Insemination of heifers is prohibited. During the period of recovery, the introduction of heifers from supplying farms into the complex and onto the farm is stopped, and in the future, the addition of new livestock to them as off-farm enterprises for raising heifers is not allowed.

At beef production complexes and other fattening farms, when tuberculosis is diagnosed, all animals in the disadvantaged group are branded with the letter “T” and slaughtered within 15 days. The remaining livestock is examined every 60 days for tuberculosis using the allergic method or the issue of selling all animals of the complex (farm) for meat is decided.

When infection of cattle with the causative agent of avian tuberculosis or atypical mycobacteria is established, and also when animals that react to tuberculin are detected in a free herd (on a farm), but tuberculosis has not been established in them by previous studies, the herd (farm) is considered free from tuberculosis.

In pig farms (on farms) where pigs have been infected with the causative agent of tuberculosis of bovine or human species, all pigs that react to tuberculin (including pregnant sows), as well as boars and fattening livestock, are immediately slaughtered. The remaining sows that do not respond to tuberculin are sold for meat after farrowing, and young animals - after growing. On dysfunctional farms, insemination of sows is prohibited. The elimination of the outbreak of tuberculosis in pigs is carried out within no more than 6 months.

Horses are examined by an ophthalmic test. Reacting animals are sent for slaughter, and the rest of the livestock is examined every 60 days until a negative single result is obtained, on the basis of which the study group is recognized as free from tuberculosis.

Goats and sheep are examined with a tuberculin test. Those who respond are sent for slaughter, and the rest of the livestock is tested for tuberculosis every 60 days until a negative result is obtained for the group.

If deer (deer) in a disadvantaged herd become infected with tuberculosis, the animals are tested for tuberculosis until negative results are obtained for the herd. Animals that are clinically ill and react to tuberculin are sent for slaughter. Deer (deer) are examined for tuberculosis in November - February (males additionally in July - August), and young animals - after they are transferred to winter roads.

When tuberculosis is established in dogs, animals reacting to tuberculin (females along with their offspring) are killed, and their skins are used without restrictions. In nurseries, animals from the disadvantaged group are tested with tuberculin every 60 days until negative single group results are obtained.

When tuberculosis is detected in fur-bearing animals, they are subjected to a clinical examination, sick animals (females along with their offspring) are isolated. During the period of skin maturation, they are fed daily tubazide in therapeutic dose(according to the instructions for its use). The animals are killed after the skins have matured, which are used without restrictions. For the rest of the animals in the disadvantaged group (farm), tubazide is added to the feed in a prophylactic dose; minks in such a farm are vaccinated with the BCG vaccine for preventive purposes.

A fur farm (farm) is considered healthy if during one production period (from whelping to slaughter for skins) no changes typical for tuberculosis are found in the organs of dead and killed animals.

In poultry farms, when tuberculosis is diagnosed, all the birds in the affected poultry house (zone, workshop, department) are handed over for slaughter, veterinary and sanitary measures are carried out, and after the quarantine is lifted, a new flock of healthy pullets is formed. On dysfunctional farms, it is necessary to maintain cleanliness, carry out disinfection, disinfestation, deratization, sanitary repairs of livestock premises and other veterinary and sanitary measures in accordance with current instructions.

For disinfection on farms, the following is used: a suspension or clarified solution of bleach; neutral calcium hypochlorite solution; hypochlorite or hexanite containing at least 5% active chlorine; drug DP-2; 1% aqueous solution glutaraldehyde; alkaline formaldehyde solution containing 3% formaldehyde and 3% sodium hydroxide; 5% solution of technical sodium phenolate; 20% slurry of freshly slaked lime by whitewashing three times with an interval of 1 hour.

For aerosol disinfection of cleaned and hermetically sealed premises in the absence of animals, a 40% aqueous solution of formaldehyde is used.

The surface layer of soil is disinfected with 3% alkaline solution formaldehyde or bleach. Pasture areas on which herds unaffected by tuberculosis were grazed can be used after 2 months in summer time in the southern regions and 4 months in the rest.

Manure, bedding and food residues from animals sick or suspected of being sick or infected with tuberculosis are destroyed or disinfected by biological, chemical or physical methods.

Livestock farm (department), farm, locality are recognized as recovered from tuberculosis after the complete cessation of the disease in animals with this disease, the delivery of all sick animals for slaughter, and the implementation of a set of final organizational, economic, veterinary and other measures provided for in the instructions for combating the disease. An act on this is drawn up, on the basis of which the chief veterinarian of the district (city) submits to the local authorities a proposal to remove the tuberculosis quarantine from the unfavorable point.

In farms recovered from tuberculosis, after the quarantine is lifted, restrictions on the sale of animals for breeding and production purposes and showing them at exhibitions, cattle broods for four years, and pigs for one year remain limited.



– an infectious disease of animals and humans caused by mycobacteria Mycobacterium tuberculosis , discovered by Robert Koch in 1882.

This type of bacteria rarely affects other mammals, and cats are resistant to this subspecies. Can also cause human illness M.bovis and complex M.avis – a group of related mycobacteria that are widespread in nature and among animals.

In the vast majority of cases, the causative agent of animal tuberculosis is the mycobacterium M.bovis. It affects cats, dogs, ferrets, badgers, and cattle. Cats can also become infected by drinking milk from infected cows or by contact with sick animals or by being in an environment where animals with tuberculosis live.

Another bacterium that causes this disease in actively hunting cats and (including voles) is M. microti .

Routes of transmission

A nutritional route of transmission is possible - through infected milk, meat (for example, infected cattle or mice).

The main route of transmission of infection is aerogenic. Mycobacteria are contained in sputum released from the respiratory system when coughing. Droplets of sputum settle on various objects, and when dry, they can rise into the air and be inhaled by healthy animals. The entrance gates are the mucous membranes of the mouth, tonsils, and bronchi.

Infection occurs much less frequently by contact : from animals with tuberculosis through damaged skin or mucous membranes.

Sustainability in the environment

The pathogen is able to maintain its viability in a dry state for 3 years. Resistant to acids, alkalis, alcohol. But under the influence of sunlight, the culture dies in 1.5 hours, and ultraviolet rays- in 2-3 minutes. When boiling, death occurs after 5 minutes, when pasteurizing - after half an hour. Therefore, the most effective measures to reduce the infection of a room due to tuberculosis are ventilation and exposure to UV rays.

Clinical signs

Like everyone else infectious diseases, tuberculosis has a latent (hidden) period, which ranges from 3-8 weeks to 1 year.

If the disease begins as a result of eating infected foods (for example, drinking unpasteurized milk from an infected cow, or eating sick rodents), then the intestinal form of the disease occurs with inflammatory granulomas in the intestines, leading to vomiting, loss of appetite and weight. However, infection of animals through the skin occurs more often (with bacteria acquired through a bite). In this case, the symptoms of tuberculosis in animals are expressed in the appearance on the skin of non-healing ulcers and/or dense nodes, which may be lymph nodes. The lymph nodes are swollen and become noticeable, often this may be the only sign or the most obvious. In some cases, the infection spreads to surrounding tissues (muscles, bones), which can lead to lameness. The disease progresses slowly, weakness and weight loss develop. If infection occurs through the respiratory system, then, as a rule, the main symptom is a cough.

Risk to humans

All mycobacteria that cause tuberculosis pose a potential threat to humans, although the risk of tuberculosis spreading from cats and dogs to humans is quite low. However, M. tuberculosis and M. bovis are common cause occurrence of the disease in humans, therefore, if these bacteria are detected in pets, treatment is not recommended.

Diagnostics

Diagnosis of animal tuberculosis is carried out taking into account clinical signs. It is necessary to exclude the formation of lesions in the lungs, as well as the spread of infection to the bones and muscles. Blood tests may show and/or, which may be secondary to the formation of granulomas.

To identify mycobacteria, the following is carried out:

Staining smear with microscopy
from damaged areas followed by staining the smear
Growing a culture of mycobacteria
PCR (extraction of pathogen DNA modern method polymerase chain reaction)

Treatment

Because this human disease is caused mainly by bacteria M.bovis And M. tuberculosis , treatment of animals that also become ill due to these mycobacteria is not recommended. When an animal is infected M. mycroti the response to treatment is positive.
Treatment is long-term (often several months), and a combination of antibiotics is often used. In most cases, antibiotics from the groups of fluoroquinolones, macrolides, etc. are used.