Thirty‐two cats with effusive or non‐effusive feline infectious peritonitis treated with a combination of remdesivir and GS‐441524

Abstract Background GS‐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. Objectives Describe treatment protocols, response to treatment and outcomes in cats with FIP treated with a combination of PO GS‐441524 and injectable remdesivir. Animals Thirty‐two client‐owned cats diagnosed with effusive or non‐effusive FIP including those with ocular and neurological involvement. Methods Cats 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. Results Cats 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. Conclusions We 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.