350 TUBERCULOSIS AS A TYPE OF BACTERIAL DISEASE 



Tuberculosis in the Horse is relatively very rare. It attacks 

 the organs of the abdominal cavity, especially the glands ; it affects 

 the lung secondarily as a rule. The cases are generally isolated .ones, 

 even though the animal belongs to a stud. Nocard holds that the 

 bacillus obtained from the pulmonary variety is like the human 

 type, whilst the abdominal variety is more like the avian bacillus. 



Dog. — Nocard says: "If the dog can become tuberculous from 

 contact with man, the converse is equally true. Infection is at any 

 rate possible when a house-dog scatters on to the floor, carpet, or 

 bed, during its fit of coughing, virulent material, which is rendered 

 extremely dangerous by drying, especially for children, its habitual 

 playmates. The most elementary prudence would recommend the 

 banishment from a room of every dog which coughs frequently, even 

 though it only seems to be suffering from some common affection of 

 the bronchi or lung." * 



Birds. — Tuberculosis is a common disease among birds of the 

 poultry-yard: poultry, pigeons, turkeys, pea-fowl, guinea-fowl, etc. 

 They are infected almost exclusively through the digestive tract, 

 generally by devouring infected secretions or organs of previous 

 tubercular fowls, and though very susceptible in this way, birds can 

 consume large quantities of phthisical sputum without becoming 

 tubercular. Whatever the position or form of avian tuberculosis, the 

 bacilli are present in enormous numbers, and are often much shorter 

 but sometimes longer than those met with in tuberculous mammalia, 

 and grow outside the body at a higher temperature (43° C). They are 

 said also to be more resistant and of quicker growth. The species 

 is probably identical with Koch's bacillus, though there are differences 

 (Maffucci). In the nodule, which is larger than in human tuber- 

 culosis, there are few or no giant cells, and it does not so readily 

 break down. Guinea-pigs and other animals are not so readily 

 infected with avian tubercle as mammalian. The writer has prepared 

 a number of histological specimens illustrating the comparative 

 pathology of tuberculosis, particularly in birds which have died of 

 the disease in the Zoological Gardens, London, including guan, quail, 

 ostrich, rhea, currasow, swan, cuckoo, vulture, goose, eagle, fowl, 

 pheasant, parrot, etc. In most cases the disease affects the organs 

 of the alimentary canal, especially the liver. The lungs are rarely 

 affected except secondarily. The disease frequently develops rapidly 

 like an acute infective disease, and the bacilli may often be found in the 

 tissues arranged in large colonies, as in leprosy in the human tissues. 



The bacillus of avian tubercle differs from the organism of 



tuberculosis in mammals in the appearance of the cultures and 



the temperature conditions. Fischel, who worked under Huppe's 



direction, says both micro-organisms are of one and the same kind 



* Animal Tuberculosis, p. 129. 



