64 CANINE AND FELINE SURGERY 



walls have become indurated, and, in addition to the 

 scraping, it may be necessary to destroy them with caustics 

 or astringents before healing can be accomplished. 



Curettes are made in different sizes, and the spoon-shaped 

 part may have its edge sharp or blunt. 



Fistulas. 



Definition. — A fistula is a wound which has existed for 

 some time, communicating between a mucous surface and 

 the exterior. It is most commonly met with in the dog 

 and cat in connection with the mouth, anus, parotid gland, 

 and stomach. 



Diagnosis. — To be sure whether one is dealing with a true 

 fistula or merely a sinus, the patient should be put under 



Fig. 40. — Curette or Volkmann's Spoon. 



observation for a short time, and the discharge noted ; a 

 probe should be carefully passed, and a blunt director intro- 

 duced to collect some of the contents of the interior. 



Treatment. — This is sometimes tedious, although if per- 

 severed in will generally bring success. The lining mem- 

 brane will probably have become indurated, and will need 

 cautious removal before the edges can be persuaded to unite. 

 The possible presence of some foreign body, too, must not 

 be overlooked, and, if present, its removal should be the 

 first consideration. Caustics, astringents, and antiseptics 

 are then used at the discretion of the surgeon. It is quite 

 impossible to lay down any specific treatment which will 

 cure all fistulae. 



Ulcer. 



The term ' ulcer ' is given to a wound which shows no ten- 

 dency to heal. As a rule its edges are ragged, raw, and sore. 



