258 



VETliKINARV PATliULUi:V. 



gestion, and usuall}- occurs upon a surface because infection is 

 more likely to occur there, rarenchymatous mammitis of the 

 bovine is frequently succeeded by necrosis and putrefaction of 

 the necrotic tissue (gangrene). Gangrenous pneumonia is not 

 uncommon and may be the result of embolic metastasis of organ- 

 isms from septic metritis, etc., nr it may be induced by medica- 

 ments introduced into the lung. 

 Miscclhvicoiis. 



1. Senile Necrosis. — This is a type of necrosis occurring in 

 old age. It is not uncommon in old dogs and aged horses, and 

 is usually the result of inelasticity of the arteries and an insuffi- 

 cient suppK- of nutrition. 



2. Fatty Necrosis. — This is a conditiim characterized by the 



Fig. IS.'j.— MulliDlf Fatty NecnisiB. 



Fat cells und' ^,^oili3 disiutegratiun, bi-causi- "i Sapnnificatirtn. 



conversion of fat into fatt}- acid and glycerine, tliat is, saponifica- 

 tion of fat. The name fatty necrosis is a misnomer, as the condi- 

 tion is not necrosis. It should be called saponification of fat. In 

 fact, a fulh- de\'eloped fat cell represents that amount of stored, 

 available food, and there is in reality no vitality in the cell, and 

 necrosis in dead tissue is not conceivable. Again, the real exist- 

 ing condition is saponification of the fat, not necrosis. The prob- 

 aljle cause of fatty necrosis is resorption of steapsin induced by 

 pancreatic disturbances, althougii steapsin ma^' be absorbed from 

 the intestine. Some four or five cases have been observed in the 

 dog, se\'eral cases in the slieep, and one horse was examined 

 that y. as aftected vrth fatty necrosis. In each of the above cases 



