Radiological diagnosis of rectocutaneous fistulas in a cat - a case report

Abscess and perirectal fistulas are common in humans but not so in animals. Fistulas located in tissues surrounding the anus are usually described in the course of furunculosis in dogs. This study presents the case of a one-year-old cat in which two rectocutaneous fistulas had formed. This process was a result of the chronic inflammation of tissues around the base of the tail due to the drainage of an abscess. The animal was referred for radiological examination with clinical signs of dyschezia. Faecal material was discharged only through the fistulas situated on both sides of the tail. The aim of the radiological examination was to preoperatively determine the course of the fistula tract and to identify their internal openings. Fistulography revealed that both fistulas were connected with each other and with the rectal lumen. Their external opening was located at the height of the 4th caudal vertebra, 1.5 cm (fistula on the right) and 2 cm (fistula on the left) from the wall of the rectum. The fistula located on the right side branched cranially. The rectal lumen in this area was significantly narrowed. Abscess formation resulting in the development of rectocutaneous fistulas has not yet been described in dogs or cats. In the present case, fistulography made it possible to identify directly the source and course of the fistula canal. This examination should be complemented by other diagnostic modalities, such as a contrast examination of the gastrointerstinal tract, ultrasound evaluation, and magnetic resonance imaging