DISEASES OF SWINE 485 



ease had never been seen before, which resulted from tuberculous 

 attendants who were in the habit of spitting in the hogs' feed and 

 about the premises. (B. A. I. B. 144.) 



Hogs are very susceptible to tuberculosis and may be easily 

 infected by tubercle germs of either human or bovine origin. Ac- 

 cording to experiments conducted by Dinwiddie, hogs are more 

 easily infected by germs of human origin than are any other do- 

 mestic animal, while all of the species of domestic animals usually 

 experimented on are easily infected by tubercle germs obtained 

 from cattle. (Okla. B. 63.) _ 



Symptoms. The distinguishing features between hog cholera 

 and tuberculosis are that in the case of tuberculosis the onset of the 

 disease is slow rather than sudden, as is the case in hog cholera; 

 likewise the progress of the disease is very slow, and the symptoms 

 exhibited by the hogs which are affected are those of general un- 

 thriftiness rather than of acute illness. Tuberculosis does not 

 show a tendency to spread rapidly through a herd of hogs, as is 

 the case in hog cholera, and the deaths, if any occur, will in the 

 vast majority of cases follow a very prolonged illness. It is ex- 

 tremely rare that an apparently healthy hog will die quickly from 

 tuberculosis. It is possible, of course, for a whole herd to show 

 signs of tuberculosis at about the same period, because of having 

 previously contracted the disease from the same source and at the 

 same time, as, for instance, through the feeding of tuberculous 

 skim milk. But in this case the hogs have caught the infection 

 from the skim milk, and not from each other. 



In cases of tuberculosis the post-mortem changes which may 

 be found in the organs consist of whitish or grayish consolidated 

 areas in the lungs, with sometimes a yellowish cheesy-like center. 

 Similar areas, though not so large, are found in the liver, and in 

 the case of the spleen we find nodules of varying size, some as large 

 as an acorn. These nodules project above the surface of the spleen. 

 They are whitish looking, and when cut are found to be of a tough, 

 fibrous nature, the appearance of this organ being entirely differ- 

 ent from that found in hog cholera. In tuberculosis the bloody 

 points in the kidneys are absent, but ulcerations may be found in 

 the intestines. These are usually in the small intestine rather 

 than in the large intestine, and instead of being round and raised 

 and button like, as in hog cholera, they are rather irregular in 

 outline and depressed below the surface of the surrounding healthy 

 tissue, indicating a destruction or eating away of the inner lining 

 of the intestines. 



Tuberculosis frequently affects the lymphatic glands, but the 

 changes which this disease causes can hardly be mistaken for lesions 

 of hog cholera, for in tuberculosis the inner portion of the gland 

 is broken down to a yellowish, cheesy mass which is not at all like 

 the lesions of hog cholera. (F. B. 379.) 



Tuberculous growths may be found attacking lymph glands 

 in widely separated parts of the body. Indeed, a most extensive 

 development of the disease has been reported in pigs from 8 to 



