The Abdomen 



197 



syringe with a solution of nitrate of silver or protargol (3:100- 

 5:100), or a strong tincture of iodine, reinsert the nozzle and inject 

 the solution. 



In a day or two a painful but regenerative local suppurative 

 inflammation follows, and the matter can be squeezed out at inter- 

 vals. 



Failing by this procedure, the animal must be anesthetised, a 

 probe-pointed grooved director inserted, and the pouch opened up 

 and laid bare to the intestinal canal. The pouch is then irrigated 

 and its walls either cauterised or scraped with a sharp curette. 



ANAL FISTULA. ANAL SINUS. 



True anal fistula is rare. As has been pointed out elsewhere, 

 the term fistula comprehends any abnormal tract having two orifices 

 of discharge, while the term sinus is more properly applied when 

 there is but one orifice of discharge. An anal fistula to be true 

 and complete must have two orifices, one situated in the rectal 

 mucosa, the other in the perianal cuticle. When it has but an ex- 

 ternal orifice and the other extremely in a cul-de-sac it is incom- 

 plete, or more properly 

 a sinus. The majority 

 of abnormal tracts about 

 the anus are tracts of 

 discharge leading from 

 sup p u rating anal 

 pouches, opening exter- 

 nally just without" the 

 anus. At the same time 

 there exists the normal 

 excretory orifice within 

 the anus, but the fact of 

 the existence of the latter does not make the condition one of fis- 

 tula. It is rather one of sinus. 



However, true fistula does sometimes occur as a result of 

 wounds caused by lodgment of foreign bodies, particularly sharp 

 fragments of bone, and other tracts arise from malignant neoplasms, 

 tuberculous abscesses, purulent prostatitis, disease or lesions of 

 neighboring bones, and external traumatism. 



Symptoms and Diagnosis. As with inflammation of the anal 



No. 43. Anal Slnns. 



