222 DISEASES OF THE RECTUM AND ANUS 



(c) Oxyuris ambigua, found in the rabbit. The male is 

 3 mm. to 5 mm. long, and the female 8 mm. to 11 mm. They 

 are white fusiform worms the body terminating in a sublated 

 or suddenly tapering tail. 



Symptoms.— These parasites, by producing irritation to the 

 rectal mucosa, induce severe pruritis, causing the animals to 

 bite or lick the anus and often slide along on the floor to 

 relieve the intense itching. The parasites are often seen 

 projecting from the anal opening, or observed being passed 

 with the feces. Aside from the disagreeable symptoms in- 

 duced they do not effect much change to the mucosa, and no 

 general symptoms are observed. 



Treatment.— Oleaginous or saline infusions injected into 

 the rectum with a syringe are usually sufficient to destroy 

 them. These injections may be repeated every few days 

 until the symptoms disappear. 



NEOPLASMS IN THE RECTUM. 



Tumors of the rectum and around the anal opening are 

 occasionally observed, more commonly in dogs than in any of 

 the other small animals. The most common tumors found in 

 .the rectum are adenocarcinomas or adenomas. Epithe- 

 liomas also occur located outside the anus and originating 

 from the skin. Occasionally are found fibromas and sarcomas 

 originating from the periproctal connective tissue. 



Symptoms.— The adenomas or adenocarcinomas found on 

 the rectal mucosa or margin of the anal opening interfere 

 with defecation and cause straining. They usually appear as 

 fungus-like growths with ulcerated, bleeding surfaces. Their 

 rapid development is characteristic. Epitheliomas occur as 

 a wart- or cauliflower-like growth with a rough uneven surface 

 situated in the skin around the margin of the anal opening 

 and often involving the anus, skin and periproctal connective 

 tissue. These vary in size, may appear singly or multiple 

 and often show an ulcerated surface, with a fetid discharge. 

 Fibromas are usually quite large and grow from the peri- 

 proctal tissue on one side of the anus. They may be two or 

 three inches in diameter, and are characterized by their 



