BackgroundGS‐441524 has been successfully used to treat feline infectious peritonitis (FIP) in cats. However, the use of its prodrug, remdesivir, in combination with a PO GS‐441524 containing product for the treatment of FIP has not yet been described.ObjectivesDescribe treatment protocols, response to treatment and outcomes in cats with FIP treated with a combination of PO GS‐441524 and injectable remdesivir.AnimalsThirty‐two client‐owned cats diagnosed with effusive or non‐effusive FIP including those with ocular and neurological involvement.MethodsCats diagnosed with FIP at a single university hospital between August 2021 and July 2022 were included. Variables were recorded from time of diagnosis, and subsequent follow‐up information was obtained from the records of referring veterinarians. All surviving cats were observed for the entire 12‐week treatment period.ResultsCats received treatment with different combinations of IV remdesivir, SC remdesivir, and PO GS‐441524 at a median (range) dosage of 15 (10‐20) mg/kg. Clinical response to treatment was observed in 28 of 32 cats (87.5%) in a median (range) of 2 (1‐5) days. Twenty‐six of 32 cats (81.3%) were alive and in clinical and biochemical remission at the end of the 12‐week treatment period. Six of 32 cats (18.8%) died or were euthanized during treatment with 4 of the 6 cats (66%) dying within 3 days of starting treatment.ConclusionsWe describe the effective use of injectable remdesivir and PO GS‐441524 for the treatment of FIP in cats. Success occurred using different treatment protocols and with different presentations of FIP including cats with ocular and neurological involvement.

Background Dogs with inflammatory protein‐losing enteropathy (iPLE) that attain remission may be at risk of subsequent relapse. Objectives To determine the incidence of relapse of iPLE in dogs that have previously attained complete clinical and biochemical remission and identify associated risk factors. Animals Seventy‐five client‐owned dogs diagnosed with iPLE. Methods Medical records of dogs diagnosed with iPLE based on histopathology of intestinal biopsy specimens between March 2010 and March 2020 were retrospectively reviewed. Variables were recorded from the time of investigation at histopathologic diagnosis and subsequent follow‐up information was obtained from the records of referring veterinarians. Results Twenty‐three dogs (31%) achieved sustained remission without documentation of relapse for at least 2 years. Nineteen dogs (25%) achieved remission, but then subsequently relapsed within 2 years of histopathologic diagnosis, and 33 dogs (44%) never achieved remission with disease‐associated death occurring a median of 19 (range, 3‐114) days after histopathologic diagnosis. Dogs that achieved remission and subsequently relapsed had significantly higher poor dietary compliance, as defined by frequent scavenging or changing from the recommended diet compared to dogs with sustained remission (P = .01). Conclusions Inflammatory PLE is associated with a high rate of relapse in dogs. Ensuring owners adhere to dietary recommendations might help prevent subsequent relapse in dogs with iPLE that attain initial remission.