Tuberculosis in Animals

TUBERCULOSIS IN ANIMALS. The causative agent of tuberculosis in animals are varieties of Koch's bacillus: in mammals, predominantly typ. bovinus, in birds-typ. gallinaceus, and in individual cases, typ. humanus is also encountered. Among mammals, tuberculosis is most common in cattle and swine, and among birds-in poultry breeds. The seemingly sharp morphological difference between the development of the tuberculous process, especially in cloven-hoofed animals, on the serous membranes in the form of connective tissue proliferations, "pearl tumors," and the formation of nodules with caseous necrosis, "tubercles," in the parenchymal organs of humans, for a long time delayed the development of the doctrine of tuberculosis in animals. Laennec in 1811 was the first to speak for the specificity of the nodules found at autopsies and for the identity of human tuberculosis with tuberculosis in cattle. Villemin in 1865 proved that by means of inoculations, feeding, and inhalation of tuberculous materials from sick humans, it is possible to produce in animals lesions identical to those observed in humans. However, Virchow considered that tuberculosis in animals is not observed at all, while the pearl nodes of cattle he considered to be lymphosarcoma. The works of Villemin, Saint-Cyr, Klebs, Chauveau, Bollinger, Blumberg and Lange (in Kazan), and others more and more proved the possibility of transferring tuberculosis-from cattle to humans and various animals. This dispute was resolved in 1882 by Koch, who discovered the causative agent of tuberculosis and proved that his bacillus is the culprit of the process--both in humans as well as in animals and birds.-Tuberculosis in birds was also for a long time not considered identical to tuberculosis in humans or animals. In 1868 Roloff considered it to be multiple lymphosarcoma or sarcoma, but in 1875 Polike and Gerlach pointed to the similarity of tuberculosis in birds with tuberculosis in animals and to the possibility of mutual transmission. Koch's discovery gave as it were indisputable proof of the unity of the nature of tuberculosis in birds and mammals. However, as early as 1884 Koch himself, and then Rivolta (Sch-volta) noted that it is not possible to infect chickens with tuberculosis from mammals, while Maffucci, Baumgarten, Gamaleya and others pointed to morphological and cultural differences between the bacilli of birds and mammals. From this time, the causative agent of tuberculosis in birds was isolated as a special type of tubercle bacillus; it is sometimes found in both humans and animals, causing tuberculous lesions in them. Thus, the question of the identity of tuberculosis in animals and humans was already considered resolved, when in 1901 at the London Congress Koch, after experiments conducted together with Schütz, made a statement that human tuberculosis is not identical to the pearl disease of cattle, that cattle are not susceptible to the bacillus of human tuberculosis, and that therefore Koch "does not consider it possible to recommend any measures" against human infection with the pearl disease of cattle. However, the majority of scientists spoke out against Koch's statement-some, like Behring and Nocard, on the basis of observations on the morphological and biological properties of human and bovine tubercle bacilli, and others, like Arloing, de Jong and others, citing their own experiments of successful infection of both adult cattle and calves with tuberculous materials from humans. At the present time, on the basis of the closest study of the question, we are more and more approaching the position expressed by Arloing: "one should recognize the unity of human tuberculosis and tuberculosis in cattle".-See also Tuberculosis, causative agent of tuberculosis. It should be kept in mind that only in domestic species is there a mass spread of the disease, while among wild (or rather free-living) animals, tuberculosis is observed only in those that have fallen into conditions of captivity. Apparently, artificial living conditions increase the susceptibility and decrease the resistance of animals to tuberculosis. It has never been possible to detect tuberculosis in pigeons just caught, while when kept for a long time in cages, in masses, among them begin to appear specimens affected with tuberculosis (Matveev). The development of tuberculosis among wild animals, deprived of freedom and placed in conditions of close contact with humans, a priori gives the right to assume that these animals become infected mainly from humans, and consequently in them the bacillus typ. hum. should be found predominantly, but this is not confirmed. According to observations by a large number of authors, the largest number of animal species is affected by the bacillus typ. bov., then typ. hum., and finally typ. avium. If we add to this also humans, then it should be concluded that the bacillus typ. bovinus has the widest distribution among mammals; apparently this must be explained by the fact that the bovine type bacillus is indeed the most virulent (de Jong, McFadyean and others). The influence of artificial conditions of animal husbandry on the spread of tuberculosis among them is particularly evident among cattle; thus, among gray Ukrainian (draft) oxen, little susceptible to tuberculosis when kept on pasture, the incidence of tuberculosis when kept in stables greatly increases. Hutyra and Marek state that "among animals remaining always on pasture, tuberculosis is almost completely unknown, and even among cattle temporarily kept in cowsheds, it is the less widespread the more time these animals spend under the open sky." The spread of tuberculosis in cowsheds is directly proportional to the number of animals placed in them. Januschke reports that in Czechoslovakian farms having from 1 to 3 head, 6.9% reacted to tuberculin; from 4 to 6 heads-9.1%; from 7 to 12 heads-16.2%; from 13 to 20 heads-17.3%; from 21 to 30 heads-19.9%; over 30 heads-32.99%. From the data of Shukevich, who examined Petrograd dogs, it is seen that in stray dogs he found tuberculosis in 0.13%, in indoor dogs-in 4.6%.-An essential factor in the development of tuberculosis in animals must be considered acclimatization. In a number of countries (Hungary, Denmark, Japan, USSR) it is noted that local breeds are more resistant than newly imported foreign breeds and their crosses. With the development of the doctrine of the role of filterable forms of tuberculosis, the significance of congenital tuberculosis in animals will undoubtedly be clarified, but unfortunately there are no special works devoted to this question in relation to cattle; however, the fact of the possibility of congenital infection of calves is beyond any doubt, since a number of authors report finding tuberculosis in the fetuses of cows. Meilach considers that in Germany in tuberculous cows in 6.14% of cases the fetus is infected. Nocard reports that in France in newborn calves tuberculosis occurs in 0.64% of cases, but already in the first weeks of life the percentage of calves reacting to tuberculin reaches almost 5. Subsequently, with the increase in the age of the cattle, the number of infected also increases, reaching a maximum during the period of highest productivity of the animals. This is confirmed by a large amount of slaughterhouse data and the results of tuberculin tests. The influence of sex is particularly noticeable in older ages: thus, Petrovsky on Ural cattle observed tuberculosis in bulls in 17.65%, in oxen-15.69%, in cows-62.74%, in barren cows-3.92%.-The widespread spread of tuberculosis among dairy farm cattle, besides the anti-hygienic conditions of "stable" keeping, must also be connected with the ever-increasing desire to obtain as much milk as possible from each cow. It has long been noted that it is precisely the highly productive cows, especially those subjected to early forced milking, that are the first victims of tuberculosis. Most of the record holders for milk productivity die from this scourge. The geographical distribution of tuberculosis in animals is extremely widespread. Its presence is noted in all countries of the world, however, the intensity of development is not the same, which depends on the nature and degree of development of livestock farming. On the vast pastures of the USA, in Central Africa, on many islands, tuberculosis in animals is almost unknown or occurs very rarely, while in densely populated areas, especially near large cities, among cattle and swine it becomes stationary and continuously develops. Klimmer reports the following data on the spread of tuberculosis among cattle in Saxony (the most affected country): in 1885 here at slaughter about 5% was discovered, in 1890-15.7%, in 1895-27.5%, in 1900-30.7%, in 1905-35.1%, and in 1910-41.4%. More indicative in characterizing the degree of spread of tuberculosis are not slaughterhouse data, but the results of tuberculin tests. Klimmer reports the following data: in Belgium 25% of the tested cattle react to tuberculin, in Germany-60%, in Finland-25%, in France-40%, in England-40%, in Norway-8.5%, in Austria-18%, in Romania-16%, in tsarist Russia-15%, in Switzerland-50%, in Hungary-40%, in Australia-^0%, in Brazil-20%, in Canada-6% and in the USA-15%. In the USSR according to the data of the veterinary department of the NKZem of the RSFSR among cattle there are the following figures (number of head): Tuberculin tests Years Number tested Reacted Percentage 1929 90,979 4,5 1930 115,649 8,344 7,2 1931 307,661 12,330 4,0 1932 696,180 14,617 2,4 Depending on the quantity and virulence of tubercle bacilli, as well as on the resistance of the animal to them, from the moment of their introduction into the organism until the complete development of the tuberculous process or even the death of the animal, years may pass.

During this same period, each infected animal is a bacillus carrier, and at the same time often also a bacillus excretor. The constant cleansing of the body of tubercle bacilli occurs mainly through their elimination via the liver, bile into the duodenum, and further. When the mucous membranes are affected or when previously isolated individual tuberculous foci are opened, the tubercle bacilli are removed from the body with pathological excretions (sputum, pus, uterine discharge, etc.). The excretion of tubercle bacilli with milk occupies a special place (see below). An animal that is clinically completely healthy but actually infected can be a periodic excretor of infection with feces for a considerable period of time. The daily amount of feces of an adult animal equals 12-15 kg, and in this mass is embedded an indeterminate number of tubercle bacilli, especially many of them can be present when the animal begins to swallow sputum (animals rarely spit it out). According to Oster tag, in these cases it is sufficient to introduce 0.001 g of feces to a guinea pig to cause its death from tuberculosis. Cadeac and Bournay confirmed this in rabbits, and Zagari established the excretion of the tubercle bacillus in the feces of dogs fed human sputum. The tubercle bacillus was found in the excretions of pigs. Ferrannini proved that the tubercle bacillus, after passing through the digestive tract, is not weakened. Droplets of sputum scattered by animals when coughing can undoubtedly also serve as a source of infection, especially when animals are kept in crowded conditions. Dust, into which the droplets settling on objects surrounding sick animals are transformed, also has the same significance; the dispersal of infection with feces is also of importance: with it, infection is spread even from the premises (manure). The milk of infected animals can contain tubercle bacilli not only when the mammary gland is affected, but also when the supramammary glands are diseased, which occurs twice as often as affection of the udder, as well as during bacillemia. The tubercle bacillus is excreted with urine when the renal pelvis, ureters, and bladder are affected, in disseminated kidney tuberculosis, during bacillemia, as well as in tuberculosis of the sexual organs due to the admixture of their secretions. The meat of infected animals has until now been considered almost harmless in terms of transmission or spread of infection when the lymph nodes embedded in the muscles are intact; numerous experiments of feeding animals with pure meat from tuberculous animals gave negative results, but when the lymphatic system is affected, the meat can serve as a source of infection, especially the meat of severely emaciated chronic cases and in acute generalized tuberculosis. The possibility of long-term bacillus carriage with periodic or constant bacillus excretion makes each infected animal to a greater or lesser degree dangerous as a disseminator of infection. Its transmission from one animal to another in most cases occurs through infected excretions with which all objects surrounding a sick animal are contaminated, or directly due to the consumption of affected organs. Under the conditions of stable housing of domestic animals, the possibility of systematic repeated infections increases, which is especially dangerous (Kadimet). The main gates of infection entry in animals are the digestive apparatus. The milk of infected animals and its by-products (whey, serum, slops after cleaning milk utensils and equipment) in an unboiled state often serve as sources of mass infection in pigs, calves, etc. The consumption by cats and dogs of sputum from phthisical patients serves not only as a source of infection for the animals themselves but also as a means of spreading it with their feces. The possibility of airborne infection among animals when kept in crowded conditions is not excluded, especially in premises where there are coughing sick animals. Infection with tuberculosis through the skin in animals is generally observed very rarely, more often in cats and dogs; in pigs and bulls, cases of infection through castration wounds have been noted. During mating, mutual infection is possible. For cattle, the main source of infection is cattle itself, but there are observations of infection of these animals with the avian bacillus from chickens and individual cases of infection of calves from humans (disputed). For other animals, the main source of infection in most cases are products of cattle. Many animals are susceptible to all three types of tuberculous causative agent (e.g., pigs, goats). Cats are more often infected with typ. hum., dogs with typ. bov. The introduction of new animals, insufficiently examined for tuberculosis, into a healthy herd often serves as a moment of bringing in infection. The susceptibility and resistance to tuberculosis among animals and birds are extremely diverse, depending on the species, breed, sex, age, acclimatization, breeding conditions, housing, intensity of exploitation, and even individuality. We do not know of animals that would be absolutely insusceptible to tuberculosis. Patho-anatomical changes in various species of animals have somewhat different characters. In cattle, goats, and sheep, a tendency to abundant connective tissue proliferations (pearly tumors) with dry caseation and abundant lime deposition is noted, and in cattle the caseation and lime are colored yellow-orange, while in goats and sheep they are matte white; in goats, cavities in the lungs are often encountered. In horses, abundant formation of caseation with its softening (lime deposition is rare), and severe hypertrophy of the affected lymph glands is observed. In pigs, pearly tumors are very rare; small foci with cheesy, lime-rich decay predominate. In dogs, nodules in the lungs often resemble sarcoma, but sometimes the foci consist of stretching pus or contain dry white cheesy masses; pearly nodules are often encountered. In birds-chickens, geese, and ducks-tuberculosis of the lungs is rare; the intestine, liver, and spleen are most often affected, where colorless gelatinous or yellow and crumbly, sometimes calcified nodules are formed; for parrots, horn-like growths on the eyelids, corners of the mouth, and in the oral cavity are characteristic. In cattle, tuberculous changes in the lungs are found in various parts of them, more often in the posterior lobes. Simultaneously with the process in the lungs, affection of the mucous membrane of the adjacent bronchi, trachea, larynx, nose, and nasopharynx can be observed. In other parenchymatous organs-liver, spleen, kidneys, lymph glands, and mammary gland-nodules and conglomerates of them with abundant caseous decay appear, with enlargement, hardening, and nodularity of the organs themselves. When the uterus and its horns are affected, the process is localized on the mucous membranes, cotyledons, in the muscles, and serous membranes. The main gates of infection in animals are the digestive apparatus, while the lungs are less often affected, and the sexual routes even less so. Tubercle bacilli entering with food penetrate through the mucous membrane of the intestine, where they are completely or partially retained by the lymph glands, in which the first focus develops, or are carried away with the lymph flow through the thoracic duct into the lungs; then in the lung tissue or in the lymph nodes the primary process develops, and from here the seeding of the nearest areas and the spread of infection via the lymphatic and circulatory systems occur. This point of view, according to which primary lung tuberculosis arises through alimentary infection, has recently encountered decisive objections (Bruno, Lange); opposed to it is the view according to which the cause of primary lung tuberculosis is usually airborne infection. The frequency of affection of various organs in cattle with tuberculosis according to Wolferz is as follows: lungs-23.26%, pleura-10.05%, liver-9.26%, peritoneum-3.4%, udder-1.68%, others-tenths and hundredths of a percent (muscles-0.03%, bones-0.04%). Of the lymph glands, the following are affected: retropharyngeal-in 54.32%, bronchial-in 53.80%, mediastinal-in 55.38%, portal-in 12.1%, external inguinal-in 1.97%, and submaxillary-in 0.1%. The process was localized in only one gland: in the retropharyngeal-36.1%, in the mediastinal-9.0%, in the bronchial-8%, in the portal-0.1%. In all other cases, the tuberculous process involved two groups and more glands and the corresponding organs. The frequency of affection of organs and glands in calves (according to Bergmann): portal glands-34.6%, bronchial-23.0%, liver-17%, mesenteric glands-14%, lungs-9.6%, hepatic glands-7.7%. In pigs: affection of submaxillary glands-83%, lungs-65%, pulmonary lymph glands-60%, portal-52%, liver-46%, mesenteric glands-44%, tonsils-32%, spleen-31%, iliac glands-14%, lumbar-13%, inguinal-11%, thoracic gland-11%, bones-10%, pleura-4%, peritoneum-4% (Chausse). In dogs: in the lungs-80%, on the pleura, in the bronchial and mediastinal glands-60%, in the kidneys-45%, on the peritoneum and in the mesenteric gland-30%, on the pericardium-25%, in the spleen-10%, in the heart muscle-5% (according to Cadiot). In birds: in the liver-98.6%, in the spleen-93.1%, in the lymph glands-70.3%, in the lungs-41.2%, in the bones and joints-22.8%, in the oviduct and ovaries-4.1% (Vosgien). The clinical diagnosis of tuberculosis in animals is often extremely difficult, since from the moment of introduction of tuberculous infection under natural conditions of infection to the appearance of clinical signs, months and years may pass.

With the further development of the process in lung lesions, a weak, dry, wheezing cough is noted, occurring in paroxysms when the animal stands up, with a sharp change in air, or with rapid movements. Sometimes fluctuations in temperature of 1-1.5°C can be detected. Further, the cough becomes strong and sharp, often dry, and sometimes wet, with the expectoration of sputum. Animals become lethargic, appetite decreases, loss of body weight occurs, and finally they become emaciated, breathing becomes frequent and difficult, with frequent coughing and abundant secretions, and periodically the temperature is 40°C and above. Percussion and auscultation in the initial periods may give no results, as the process can often be located under the shoulder blades, but in more developed processes, areas of dullness and dry or moist rales can be detected. In T. of the pleura, increased sensitivity to pressure in the intercostal spaces is sometimes observed. With lesions of the trachea and larynx, there is a painful and spasmodic cough, sometimes aphonia occurs. Tuberculosis of the peritoneum can occur without clearly expressed symptoms, just as T. of the intestine does. In adult females with lesions of the genital sphere, nymphomania is observed, often, especially in the first half of pregnancy, abortions with subsequent metritis. With the appearance of emaciation, a sharp increase in peripheral lymph glands is often noticeable. With lesions of the mammary gland, if the process is localized in the interstitial tissue, diffuse swelling of the entire corresponding quarter of the udder quickly develops, followed by its hypertrophy and hardening; with localization in the lobules of the mammary gland, a small hardened area slowly increases, the gland becomes dense and nodular; the posterior lobes are more often affected than the anterior ones. In chronic cases, all these signs develop slowly, without initially giving a clear picture, but there are cases of acute course, in which all signs quickly increase, and death occurs in several weeks. In pigs, a form of "scrofula" is often observed. The lymph glands of the neck, larynx, and pharynx are dense, nodular, painless, often enlarged to the size of a fist, fused with the surrounding tissue, sometimes they suppurate and open outward, discharging purulent-caseous masses. In T. of the lungs, the increasing cough is often accompanied by vomiting, animals quickly lose weight and die in 3-4 weeks. With lesions of the joints and epiphyses of the bones of the extremities, the joints are painful and greatly swollen. In T. of abdominal organs, the process develops very slowly: animals lose weight, are listless, lose appetite, constipation appears, alternating with diarrhea, meteorism; when examining the abdomen, uneven voluminous tumors-enlarged lymph glands-can be palpated; over several months the animal weakens and dies slowly. In dogs, the process is more often localized in the lungs than in the intestine. A capricious appetite, emaciation, general lethargy, easy fatigue, often subfebrile temperature, short dry cough, often with vomiting are noted. In the lungs-dry and moist rales, sometimes bronchial breathing. Exudative pleurisy and pericarditis often develop. In T. of abdominal organs, besides emaciation and periodic diarrhea, nothing else can be detected. On the extremities in dogs, arthropathy sometimes develops-diffuse, often symmetrical thickenings of the bones and subcutaneous tissue. In cats, the course of T. is generally similar to its development in dogs, but in them cases of chronic course are more often observed, and sometimes clinical recovery, especially with intestinal involvement. More acute forms are accompanied by exudative pleurisies and peritonitides. Often the cough is with vomiting, with diarrhea-liquid, foul-smelling feces. Cutaneous T. in the form of separate nodules in flat ulcers with pale-red, torpidly granulating bottom is observed on the nose, on the eyelids, on the neck and on the head. The scarcity of specific signs of T., and sometimes the difficult detection of them due to the slow development of the disease often do not make it possible to differentiate the nature of the disease without the use of specific methods, and here the most accessible is tuberculin diagnosis. Tuberculin tests are used in veterinary practice in several forms, namely: a) Conjunctival. 2-3 drops of tuberculin are instilled into the conjunctival sac of the eye. After several hours, inflammatory phenomena develop: hyperemia, moisture (tearing), edema, and fibrinous exudate with a large admixture of leukocytes. Examination after 4, 8, and 12 hours. By 12 hours, fading often occurs. To obtain more distinct reactions, the introduction of tuberculin into the same eye is repeated after 4-5 days, b) Intradermal. 2-3 drops of tuberculin are injected with a syringe into the superficial layers of the skin of a shaved area on the neck or into the subcaudal fold. After 48 hours-a well-developed tumor of 0.7 cm or more in size. Sometimes an increase in body temperature is observed, c) Intrapalpebral. 2-3 drops of tuberculin are injected into the skin of the eyelid with a thin needle. After 10-12 hours, edema on the skin of the eyelid, phenomena of conjunctival reaction on the mucous membrane; often an increase in body temperature, d) Subcutaneous. After establishing the average body temperature, 1.0 is injected into adults, 0.5 into calves on the neck, then the temperature is measured every hour after 6 hours. A positive reaction is characterized by a typical thermal curve: the temperature begins to rise 6-8 hours after injection and reaches a maximum between 11-14 hours, after which a gradual return to normal occurs. The difference between the average and maximum temperature is 1.0-1.5°C, but the decisive significance is not the absolute difference, but the specific type of curve. The reaction is often accompanied by chills, depression, increased coughing, loss of appetite. In the last month of pregnancy before calving and in febrile animals, tests are not performed. In animals with the initial process, the reaction is more pronounced than in chronic cases. It is more rational to give a conclusion about the infection of the animal after applying two methods.--In young calves, pigs, and poultry, the intradermal test gives the most indicative results. Tuberculin is injected into the thickness of the skin at the root of the ear in pigs; in poultry-into the ear or into the subcutaneous fold of the wing. Often tuberculin reactions are obtained in animals with unclear clinical signs and in their absence, then it is advisable to carry out laboratory studies of natural secretions (milk, feces, urine) or suspicious secretions of mucous membranes (respiratory or genital tracts) by inoculating them into guinea pigs or rabbits or obtaining pure cultures (Levenstein-Sumiyoshi and Goya methods). Serological diagnosis of T. in animals is not widely used in veterinary practice, nor has the method of Wildbolz (auto-urine reaction) for determining tuberculous antigen in urine received widespread application. The outcome in acute and clearly expressed chronic T. in animals is fatal; in initial, clinically unexpressed processes, subsidence and clinical recovery are possible, but only under improved hygienic conditions and in most cases only temporary. All the proposed methods of treatment for T. in animals to this time have actually not gone beyond the stage of experimental study. Only improvement of hygienic conditions of keeping animals (light, air, movement, more spacious placement) and moderate rational (not forced) exploitation of animals have practical significance. Prevention of T. in animals aims, on the one hand, at separating infected livestock from those free from T., and on the other hand, at immunization of young stock with the help of preventive vaccinations. In this respect, different vaccination methods have been proposed: "bovaccine" by Behring-dried in vacuum culture of T. typ. hum.; "tuberculin" by Koch-Schutz-a mixture of typ. hum. and typ. bov., weakened by prolonged cultivation on glycerin broth; "antifimathol" by Klimmer-bacilli of typ. hum., weakened by heating to 52-53°C and passed through the body of a salamander. Despite some effectiveness, none of these methods has received wide practical application. Instead, vaccination of calves with BCG is gaining increasing popularity, although it has not yet gone beyond the stage of in-depth study. 50 mg of vaccine is injected under the skin to a newborn calf in the first 15 days of its life. Immunity is preserved for 18 months. Vaccinated calves should be isolated from sick mothers. Preventive measures aimed at separating animals infected with T. from those free from it and at protecting the latter from infection consist in the following: 1) possible early detection of bacillus carriers by means of tuberculinization; 2) detection of bacillus excretors by timely clinical and laboratory studies; 3) separation of calves from mothers reacting to tuberculin; 4) prevention of the introduction of T. by careful control of newly arriving animals in the farm; 5) prevention of the spread of infection by feeding infected products (milk, meat); 6) thorough disinfection of premises and especially of manure from tuberculous animals. These general measures form the basis of modern veterinary legislation.

Certain methods for combating tuberculosis in cattle were proposed by Bang in Denmark and Ostertag in Germany. Bang's method is based on mass tuberculinization followed by the separation of reacting animals from non-reacting ones and raising the offspring from reacting mothers, provided they are immediately isolated after birth and fed with healthy or sterilized milk under normal hygienic conditions. Ostertag's method differs fundamentally from Bang's in that it excludes tuberculinization of adult cattle, retaining it only for testing young stock. Instead, this method requires periodic clinical examination of the herd and laboratory testing of milk, with clinically suspicious animals being isolated. This method has not found wide application. In the USSR, in newly established livestock farms, all newly introduced cattle are necessarily tested with tuberculin. Reacting animals are not admitted to the new farm. In old farms, periodic mass clinical examinations with tuberculin tests are conducted (not less than 2 times a year). Animals with open forms of tuberculosis are slaughtered; reacting animals with closed forms are separated into special herds and farms. Calves from reacting mothers are fed with boiled milk or milk from healthy cows; if they also turn out to be reacting, they are subject to slaughter. Systematic control of tuberculosis in pigs, goats, and poultry has not yet been organized in any country. Measures to protect humans from infection with tuberculosis through animal products. Milk from cows reacting to tuberculin is allowed for consumption only in pasteurized or boiled form. Meat in the presence of emaciation of the body due to tuberculosis, regardless of the spread of the process, is not allowed for food; in the absence of emaciation, it may be allowed in boiled or sterilized form, otherwise it is subject to technical utilization. With limited old, encapsulated single foci and good condition, meat is allowed for consumption after removal of affected parts or individual organs. When individual lymph glands are affected, the corresponding parts of the carcass are considered conditionally suitable and subject to boiling or sterilization. Tuberculosis of cold-blooded animals. In fish and reptiles (carp, frogs, newts, toads, lizards, grass snakes, turtles), various authors have found acid-fast and alcohol-fast bacilli, similar to Koch's bacilli, but apparently belonging to acid-fast saprophytes. According to the data of most authors, they are harmless to warm-blooded animals; however, Dubar was able to by passage of the bacillus isolated from fish to such an extent that it became highly virulent for guinea pigs, and Ozheshko, by cultivating bacilli at 37° and also passing them through guinea pigs, obtained cultures that cannot be distinguished from the bacilli of human tuberculosis. Some strains of bacilli isolated from snakes (Moeller) and a turtle (Friedmann) are capable of to an exceptional degree increasing immunity in animals against bovine and human tuberculosis.