594 ATRESIA ANT ET RECTI. 



the little animal's abdomen appears distended, colic sets in, the patient 

 stops sucking, strains and attempts to pass faeces, and when the 



Fig. 419. — Congenital malformation — atresia ani in the bitch (semi-diagrammatic). 



anus is examined it is found there is no opening. If the anus alone 

 is imperforate, the skin projects at the centre of the sphincter, rectal 

 contents may even be distinctly felt beneath it ; but, when the walls 



Fig. 420. — Congenital malformation — atresia ani et recti in the bitch 

 (semi-diagrammatic). 



of the rectum are also adherent this projection is wanting, and either 

 the anus is visibly closed or, on introducing the finger or a probe, 

 an obstruction is felt not far from the external orifice. In recto- 

 vaginal fistula excrement escapes by the vagina, and the com- 



