532 DISEASES OF SWINE 



the drainage from the floor of the mouth, and, accordingly, readily 

 becomes infected if food-carrying tubercle bacilli be eaten. In hogs 

 this is the most common site for development of tuberculosis. 

 Nearly 90 per cent, of cases of tuberculosis in the hog show in- 

 volvement of this gland. In meat inspection work this is the first 

 part of the body that is examined. 



Next in frequency comes the glands located in the ruffle fat of 

 the intestines. These glands receive the drainage from the intes- 

 tines, and when tuberculous milk or feces enter the bowel it is only 

 a short time until tuberculosis of these glands takes place. The 

 liver and spleen, together with their lymph-glands, are next in 

 frequency. Tubercles in the liver, if less than twelve in number, 

 may be the result of drainage of the intestines by the portal vein, 

 which carries blood from the bowel to the Uver. If more than 

 twelve spots are seen it is good evidence that the disease is gener- 

 alized, and the carcass should not be eaten for food. Tuberculosis 

 of the spleen can only occur when tubercle bacilli enter the blood 

 in considerable numbers, and this means that they are likely to be 

 scattered in the muscular tissues all over the body. The tubercu- 

 losis of swine is capable of producing this same disease in man, and 

 for this reason every hog carcass intended for use as human food 

 should be carefully inspected. 



In well-generalized cases tubercles may be found in the kidneys, 

 the testicles of male animals, the ovaries in the female, or even in 

 the muscles themselves. 



Tuberculosis of the lungs is not quite so common in the hog as 

 in cattle. However, the disease often is carried through the blood 

 or through the lymph until it finally reaches the thoracic cavity, 

 and then sets up tuberculosis of the lungs and of the lining mem- 

 brane of the chest — the pleura. In very severe cases the lining 

 membrane of the belly cavity may also be found to be tuberculous. 

 This form of the disease is known as tuberculous peritonitis. 



Tuberculosis in all these regions appears very much the same. 

 The typical lesion is a white, translucent, rounded body, which pro- 

 jects like a little bump above the surface of the organ. When this 

 is cut into it is found to have a more or less cheesy appearance. 

 These nodules or tubercles vary in size from that of a millet seed 

 to as large as an orange. 



