DISEASES OF THE DIGESTIVE ORGANS. 169 



FISTULA IN AMUS. 



This is a communication between a suppurating sore and the 

 terminal part of the rectum. There are usually two openings, 

 one into the gut and the other close beside the anus. The 

 rational treatment is to remove any foreign body or other cause 

 of irritation, and then passing an india-rubber cord through the 

 canal, to bring the end from the internal wound out through 

 the anus, and, stretching the rubber, to tie both together, after 

 which by its elasticity it slowly cuts its way through, while the 

 wound steadily heals behind. 



IMPERFORATE ANUS. 



This is not uncommon in young animals, and may be relieved 

 by a free incision as soon as the accumulation of dung in the 

 end of the rectum furnishes a firm pad on which to cut. The 

 incision must be made in the centre of the firm muscular rins 

 that should have encircled the opening, and which may be 

 easily felt. In mares spontaneous relief is often obtained by a 

 rupture into the vagina. If the gut as well as the opening is 

 wanting there is no remedy. 



PERITONITIS. INFLAMMATION OF THE LINING MEMBRANE OF 



THE ABDOMEN. 



This occurs in all domestic animals, and may be limited to a 

 particular part or may be general. It is mostly caused by 

 mechanical injuries, as wounds of the abdominal walls — surgical 

 or otherwise, or by rupture of an abscess of the stomach, 

 intestine, bladder, or womb. It may also result from sudden 

 changes of weather, chills from exposure to excessive cold, to 

 frigid showers or dews, or to a wet bed after perspiration and 

 fatigue. This is of course most frequent in horses and oxeu. 

 Similar exposure to cold is a common cause of peritonitis after 

 wounds of the abdomen, as in castration. 



