Perianal fistulas are chronically painful ulcerating lesions around the anus of dogs, most commonly German Shepherds, causing significant welfare impairment that responds to immunosuppressive therapy.
Perianal fistulas cause chronic severe pain affecting defaecation, movement and quality of life. Affected dogs show reluctance to sit, scooting, self-trauma and behavioural changes consistent with chronic pain. Early diagnosis and cyclosporine-based immunosuppression controls the condition in most cases. Ongoing monitoring is required as relapses are common.