Canine Rectovaginal Fistula With Anal Atresia

This research summary was reviewed in March 2025 to confirm its continued clinical relevance.

In the Literature

Rahal SC, Vicente CS, Mortari AC, Mamprim MJ, Caporalli EHG. Rectovaginal fistula with anal atresia in 5 dogs. Can Vet J. 2007;48(8):827-830.

Summary

A retrospective study evaluated 5 dogs with rectovaginal fistula and anal atresia. Affected dogs ranged in age from 1 to 3 months at the time of presentation, and histories included voiding of feces from the vulva (with or without tenesmus), which was usually noted after weaning. Although previous reports have noted no breed predisposition, 3 of the 5 dogs in this study were poodles. Clinical examination revealed atresia ani, presence of feces in the vaginal canal, abdominal distention, and discomfort on abdominal palpation in all 5 dogs and partial tail agenesis in 3 dogs. Except for one dog with clinical signs of pneumonia, all dogs were in good physical condition. Abdominal radiographs were taken in 2 of the dogs and showed megacolon secondary to fecal retention. In all dogs, the rectovaginal fistula was isolated and transected, the openings in the vulva and rectum were closed separately, and the atresia ani was repaired. All dogs defecated normally after surgery, suggesting that the megacolon was reversed. One dog had moderate rectal prolapse on day 10 after surgery, which was not noted 1 month postoperatively, and a second dog had fecal incontinence, which resolved approximately 1 year postoperatively. The dog with clinical signs of pneumonia died 2.5 months after surgery, and the cause was not determined. The other dogs were followed for periods ranging from 1.6 to 7.7 years, and aside from the one dog with fecal incontinence, normal passage of feces was observed in all dogs. The authors conclude that if surgery is performed early, rectovaginal fistula and anal atresia may have a favorable outcome.

Commentary

Rectovaginal fistula with anal atresia occurs uncommonly in dogs. There is limited information on the long-term outcome of this combination of congenital malformations. This study, in conjunction with the few existing reports, may help change our perception of surgical correction from unrewarding to a potentially more favorable outcome. Earlier recognition and treatment may show more promising results and eliminate adverse sequelae, such as chronic colonic distention, which may lead to a poorer prognosis. Imaging, including plain and contrast radiography, is recommended to grade the atresia ani, locate the fistula, and plan the surgical procedure. Other congenital abnormalities are often present as well.