Sclerosing encapsulating peritonitis in cats: a two-case report and literature review.

Case series summary: Two castrated male domestic shorthair cats (aged 8 months [case 1] and 13 years [case 2]) were presented at the Small Animal Clinic of the Veterinary Medicine University of Vienna, Austria, both with acute vomiting and distended abdomen, as well as a history of chronic apathy, recurrent vomiting and diarrhoea. Both cats underwent invasive diagnostic procedures approximately 1 month before the diagnosis of sclerosing encapsulating peritonitis (SEP), namely an exploratory laparotomy and a bronchoscopy, respectively. Abdominal ultrasound revealed severely corrugated intestinal loops and, in case 2, the presence of peritoneal effusion. A thick and diffuse fibrous capsule around the intestine was detected and removed surgically, and biopsies were taken from the affected organs confirming the SEP. Case 1 recovered well, was discharged some days after surgery and was clinically unremarkable for the next 2 years. Case 2 showed unsatisfactory improvement directly after surgery and was euthanased a few days later, as the owner declined any further therapy. Relevance and novel information: SEP is a very rare condition of unclear origins in cats. Here we describe the clinical and diagnostic imaging features, surgical treatment, and outcome of SEP in two cats. The results indicate that prompt diagnosis and appropriate interventions may improve the outcome.