Treatment of Perianal Fistulas

Before the discovery that perianal fistulas could be treated medically, surgical interventions were the only treatments available. These included cryosurgery, electrofulguration, rectal pull-through, and tail amputations. Complications were common and included rectal stricture, recurrence, and fecal incontinence. The cause is unknown, but evidence increasingly suggests that the disorder is immune-mediated. Many of these dogs also have colitis. Current treatment of perianal fistulas involves the use of cyclosporine and adjuvant topical therapies, such as tacrolimus ointment. Cyclosporine therapy is very successful, and the speaker describes his protocol and answers such common questions as, "How do I monitor therapy? What is the proper duration of treatment? What is the underlying etiology/reason why cyclosporine works? Why do some dogs respond to therapy and others not? What other ancillary treatments are effective? What other drugs can be given to inhibit cyclosporine metabolism?"

COMMENTARY: The treatment of perianal fistulas has historically involved some form of surgical intervention. Results varied greatly, and recurrence or significant complications were common. More recently, immunosuppressive drugs given orally or applied topically have resulted in cure or long-term control. This presentation describes a successful protocol for managing perianal fistulas. Other therapies and recommendations for monitoring are also discussed.