208 TUBERCULOSIS. 



but some facts regarding the disease in the lower animals 

 may be given, as this subject is of great importance in rela- 

 tion to the infection of the human subject. 



Amongst the domestic animals the disease is com- 

 monest in cattle (bovine tuberculosis), and in them the 

 lesions are very various, both in their character and dis- 

 tribution. In most cases the lungs are affected, and 

 contain numerous rounded nodules, many being of con- 

 siderable size; these may be softened in the centre, 

 but are usually of pretty firm consistence and may 

 be calcified. There may be in addition caseous pneu- 

 monia, and also small tubercular granulations. Along 

 with these changes in the lungs, the pleurae are also often 

 affected, and show numerous nodules, some of which may 

 be of large size, firm and pedunculated, the condition being 

 known in Germany as Perlsucht, in France aspommeltire. 

 Lesions similar to the last may be chiefly confined to the 

 peritoneum and pleurae. In other cases, again, the abdo- 

 minal organs are principally involved. The udder becomes 

 affected in a certain proportion of cases of tuberculosis in 

 cows in 3 per cent according to Bang but primary affec- 

 tion of this gland is very rare. Tuberculosis is also a com- 

 paratively common disease in pigs, in which animals it in 

 many cases affects the abdominal organs, in other cases 

 produces a sort of caseous pneumonia, and sometimes 

 is met with as a chronic disease of the lymphatic glands, 

 the so-called "scrofula" in pigs. In pigs tubercular lesions 

 in the muscles are less rare than in most other animals. 

 In the horse the abdominal organs are usually the primary 

 seat of the disease, the peritoneum, lymphatic glands, liver, 

 and spleen being extensively affected ; the last-mentioned 

 organ may be enormously enlarged and crowded with 

 nodules of various shapes and sizes. In sheep and goats 

 tuberculosis is comparatively rare, though cases are occa- 

 sionally met with. It also occurs spontaneously in dogs, 

 cats, and in the large carnivora. It is also sometimes met 

 with in monkeys in confinement, and leads to a very rapid 

 and widespread affection in these animals, the nodules 



