Canine Perianal Fistulas: Clinical Presentation, Pathogenesis, and Management.

Canine perianal fistulas are painful sinus tracts and ulcers that spontaneously develop in the skin around the anus. Middle-aged German shepherd dogs are most commonly affected and may have a genetic susceptibility. Although the disease was once believed related to conformational factors and primarily managed surgically, an immune-mediated pathogenesis is now recognized. Long-term medical management with immunomodulatory agents has become standard of care for canine perianal fistulas. Perianal fistulas can be debilitating and have a negative impact on quality of life of dogs and owners. Accurate diagnosis and aggressive medical therapy are key to successful management of canine perianal fistulas.