Surgical excision of primary canine rectal tumors by an anal approach in twenty-three dogs

OBJECTIVE: To describe an anal approach for excision of primary rectal tumors in dogs and to report outcome. STUDY DESIGN: Retrospective study. ANIMALS: Dogs (n=23) with primary rectal tumors. METHODS: Review of medical records (1990-2000) of dogs with primary rectal neoplasia excised surgically using an anal approach with rectal prolapse. With dogs anesthetized, the rectum was prolapsed, stabilized with stay sutures during tumor excision with 1 cm margins to the level of the muscularis, then the rectal mucosa was sutured. RESULTS: Each dog had only 1 tumor type (adenocarcinoma [8], solitary polyp [5], carcinoma [4], plasmacytoma [2], adenoma [1], leiomyoma [1], mucinous carcinoma [1], and papilloma [1]). Mean tumor volume was 3.1 cm(3) (range 0.1-37.7 cm(3)). Postoperative complications (rectal bleeding [5], tenesmus [4]) were mild and resolved within 7 days after surgery; another dog had partial mucosal dehiscence identified at 6 days. The primary tumor was incompletely excised in 1 dog (4.3%), and local recurrence occurred 16 and 24 months after surgery in 2 dogs. Outcome beyond the immediate postoperative period was known for 18 dogs, including 2 dogs still alive. Mean postoperative disease-free interval for these 18 dogs was 36.8 months (range 5-84 months). CONCLUSION: Surgical excision of tumors of the caudal rectum can be accomplished through the anus after rectal prolapse. CLINICAL RELEVANCE: An anal approach facilitated by rectal prolapse should be considered as a viable option for the surgical treatment of selected cases of tumors of the caudal aspect of the rectum in dogs.