Laparoscopic diagnosis of ischemic necrosis of the descending colon after rectal prolapse and rupture of the mesocolon in two postpartum mares.

Two mares were referred for evaluation after dystocia and rectal prolapse. Diagnostic laparoscopy, performed while the horses were standing, was used to evaluate the condition of the distal portion of the colon, rectum, uterus, and mesocolon. In both horses, laparoscopic observation revealed tears in the mesocolon of the descending colon. Exploration from the left or right flank was adequate. Because of the poor prognosis associated with the findings, euthanasia was elected at completion of laparoscopy. Tears in the mesocolon are not easily detected by use of traditional tests. Laparoscopy proved to be a more thorough means of evaluating the caudal portion of the abdomen including the digestive and urogenital tracts in these horses. As a less invasive diagnostic tool, laparoscopy can be performed earlier in the course of disease than alternative approaches for direct viewing. Furthermore, laparoscopy can be used to access the viability of tissues as well as the location and severity of lesions for prognostic purposes. The distal portion of the descending colon can also be evaluated to determine whether celiotomy with anastomosis or colostomy may be the surgical procedure of choice.