Experimental studies on rumeno-rectal fistula in calves

Abstract

Chronic tympany of the rumen is common in cattle. Rumen fistulation has been reported to be successful in the treatment of chronic tympany. Left side external fistulation of rumen has been adopted by many workers. But this was accompanied by seepage of rumen contents and soiling of the flank. While screening the available literature, no reports on an internal rumen fistulation could be found.

The effects of rumeno – rectal fistula in experimental calves were studied in the present work.

The study was conducted on 12 male calves in two groups , each group consisting of six calves. In the animals of Group – I , laparotomy was performed on the right flank and the right dorsal sac of rumen was anastomosed to the anterior part of the rectum. In the animals of Group II, laparotomy was performed on the left flank and the left dorsal sac of rumen was anastomosed to the anterior part of the rectum.

The PH of the rumen contents and the rectal washings, presence of rumen protozoa in the rectal contents, haemoglobin content, packed cell volume, total and differential leucocyte count, nature of dung and the body weight were noted before fistulation and at regular intervals after fistulation.

The animals were kept under observation for a period upto 100 days.

Closure of the fistula was performed 60 days after fistulation, in two calves, one from each group. The details as described above were noted in these animals also after closure of the fistula.

The PH of rectal contents before surgery ranged from 7.3 to 7.5. From the second day after surgery, it ranged between 7.0 and 7.2 in both the groups. The erythrocyte count and haemoglobin content showed a progressive reduction in eight animals and packed cell volume showed a reduction in 10 animals. The variation in the total and differential leukocyte counts were within normal limits. Rumen protozoans were present in the rectal contents from the second day after surgery.

Loss of body weight was noticed in all the six animals of Group –I, whereas an increase in body weight was noticed in four animals of Group – II.

The feeding habits of the calves were normal. Dung was loose in consistency from the second day after surgery and it contained more fluid soon after drinking water.

One animal of Group – I died on the 46th post – operative day, and another one was sacrificed on the 53rd post-operative day. Surgical closure of the fistula was performed in two animals, one from each group. All other animals were sacrificed between 60th and 100th post-operative day.

At autopsy omental adhesions were noticed at the site of anastomosis in six calves. The fistula was patent and had a diameter of about 2 cm in 11 animals. Rumen contents were present in the rectum. The site of anastomosis was hard to touch and no other abnormalities could be detected in the rumen and rectum. Complete encapsulation of sutures at the site of anastomosis was noticed in four calves. The healing at the site of anastomosis was complete in all the animals.

In the two calves in which closure of the fistula was performed, the healing was uneventful and there was progressive improvement in haemogram values and body weight.

It is concluded that functional rumeno – rectal fistula could be established in calves and that it did not cause any untoward clinical manifestations. There was escape of rumen contents through the fistula to the rectum. Surgical closure of the fistula could also be done successfully.