74: PRINCIPLES OP VETEKINAET SUBGEEY 



a -wound into a primary or idiopathic ulcer : as pieces of 

 necrotic tissue or foreign bodies at the bottom of a -wound, 

 continuous licking of a -wound as by dogs, the persistent 

 shaking of an injured ear (dog), etc. 



Enumerate the constitutional causes of ulcers. 



Certain specific local or constitutional diseases are fol- 

 io-wed by secondary or symptomatic ulcers, as the ulcer of 

 farcy, actinomycosis and tuberculosis, corneal ulcers folio-w- 

 ing dog distemper, etc. 



What circumstances encourage ulcer formation in tissues ? 



The more any agent directly or indirectly interferes -with 

 the circulation or nutrition of a tissue, the greater the ten- 

 dency of such a tissue to-ward ulceration. This interference 

 ■with the nutrition or circulation may be brought about, for 

 instance, by the action of pus cocci, these producing cell 

 necrosis ; or the circulation may be interfered -with by pres- 

 sure from an exudate upon the part, prolonged pressure, as 

 seen in decubitus (bedsores). Finally, corneal ulcer from 

 diminished innervation, as in paralysis of the trificial nerve 

 (neuro-paralytic ulcer). 



According to the quality of the granulations, what forms of 

 ulcers are recognized ? 

 Sluggish and painless, irritable and painful ulcers. 



According to the edges of the ulcer, what forms are recog- 

 nized ? 



The healthy or simple ulcer, -with a smooth, moderately 

 indurated edge ; and the callous, indolent or chronic ulcere 

 ■with a -wall-like, irregular, indurated edge. 



Depending on the depth of the ulcer, what forms are known 9 

 Superficial, deep, sinuous, tubular, fistulous. 



