486 HORSE, SWINE AND POULTRY DISEASES 



10 weeks old, born of healthy parents and evidently infected by 

 tuberculous skim milk. In these cases the lesions had not only 

 undergone extensive caseous degeneration, but had even become 

 partially calcified. As soon as the tubercle bacillus invades the 

 tissue changes develop, resulting in the formation of nodules or 

 tubercles which may be either translucent or of a yellowish-white 

 color. At first these tubercles are isolated and discrete, but later 

 they may coalesce and form large areas of tuberculous tissue. 

 (B. A. I. Cir. 144.) 



In the great majority of cases of tuberculosis in animals the 

 symptoms are slight and not at all clear in their indications. As 

 the functions of the body must be disturbed more or less before 

 any symptoms are apparent, it is plain that in the earliest stages 

 of the disease there are no symptoms, and that when symptoms 

 develop the disease is already considerably advanced. It is only 

 when the affected part is located where it may be easily examined 

 that symptoms are shown by which the infection may be detected 

 at a comparatively early stage. Thus when the udder or the glands 

 of the neck are the seat of tuberculosis the existence of the trouble 

 is more likely to be revealed than when the affected organ is within 

 one of the body cavities. 



Although there is a great tendency for tuberculosis to spread 

 to different parts of the body in swine, causing it to become more 

 frequently generalized with these animals than with cattle, the 

 rapidity with which they take on fat apparently enables them to 

 resist the destructive influence of the disease, at least to the age at 

 which they are generally slaughtered. Animals which come to 

 market fat and appear perfectly well just before slaughter may be 

 found quite seriously diseased. 



In some cases, however, swine may show enlargement of the 

 glands of the neck and of other parts of the body, diarrhea, emacia- 

 tion, and tubercular inflammation and swelling of one or more 

 joints. When the nutrition of the body is affected, as shown by 

 loss of flesh, the disease usually runs a rapid course and causes the 

 death of the animal in a few weeks. (B. A. I. B. 38.) 



Few hogs ever show by outward symptoms that they are af- 

 fected with tuberculosis. In fact, the hogs that disclose tuberculo- 

 sis at the time of slaughter are frequently the finest appearing 

 animals in the drove when they are brought to the abattoir. Should 

 indications of tuberculosis be present they will usually consist of 

 a general appearance of unthriftiness, which might result from 

 other diseases and therefore does not afford any very definite indi- 

 cation that tuberculosis is present. 



Where the disease has progressed to an advanced stage of gen- 

 eralization various symptoms may appear. Abdominal tubercu- 

 losis is frequently accompanied by general disturbance of the di- 

 gestive functions, and constipation or diarrhea may be shown. 

 Advanced pulmonary tuberculosis will be shown by a persistent 

 dry, harsh cough, and by acceleration in breathing, especially on 

 exercise. This cough is similar to that caused by lungworms and 



