INFECTIOUS DISEASES I49 



increases. When cut into, the diseased tissue 

 is usually yellowish and cheesy in character. 

 Sometimes, it is indurated and almost as hard as 

 cartilage. Calcareous degeneration of the nodules 

 is not often seen in hogs, as the lesions are seldom 

 of long enough standing for this degenerative 

 change to occUr. 



As the disease is nearly always contracted by 

 the ingestion of infected food, the digestive ap- 

 paratus stnd lymphatic glands (pharyngeal and 

 submaxillary) are commonly involved. The lym- 

 phatic glands become enlarged, knotty, and hard. 

 When cut open, they are made up largely of old, 

 fibrous tissue, with yellowish, caseous centers 

 scattered through it. Ulcers and small nodules 

 may be found in the intestinal walls and scattered 

 through the liver tissue, or larger nodules, vary- 

 ing in size from that of a pea to a hazel nut, 

 tough and yellowish white in color, may occur. 

 The peritoneum is ' sometimes the seat of fine, 

 granulations and lesions of the same nature, as ' 

 mentioned as existing in the liver, may be found 

 in the lungs, . spleen, and other inters 1 organs. 

 In generalized cases the muscles are sometimes 

 affected. 



Treatment. — The only successful method of com- 

 batting the disease is along the line of prevention. 

 The hogs should be kept in as healthy a condition 

 as possible by giving them proper care, feed; and 

 surroundings. Muddy, filthy pens are favorable 

 for infection, and well-drained pens, clean troughs, 



