Efficacy of a 3C-like protease inhibitor in treating various forms of acquired feline infectious peritonitis

Pedersen, Niels C; Kim, Yunjeong; Liu, Hongwei; Galasiti Kankanamalage, Anushka C; Eckstrand, Chrissy; Groutas, William C; Bannasch, Michael; Meadows, Juliana M; Chang, Kyeong-Ok

Monitoring response to treatment Cats with FIP based on pretesting and initial evaluation at the time of presentation to UC Davis were hospitalized for at least 5 days and immediately started on treatment. They were closely evaluated at least twice daily for rectal temperature, pulse, respiration, appetite and activity. Clumping litter was used, allowing for daily evaluation of stool volume and consistency, and urination. Whole blood was collected in EDTA or heparin by venepuncture prior to starting treatment, at 2 day intervals while hospitalized, at the time of discharge and at 2 week intervals for the first month and at monthly or greater intervals thereafter. Routine blood testing at each time point included at a minimum a hematocrit, total plasma protein, icterus index, total white blood cell count, differential white blood cell percentages, and absolute neutrophil, lymphocyte, and monocyte and eosinophil counts. Blood serum chemistry values were taken periodically to check for potential drug toxicities. Samples of abdominal effusions were obtained by paracentesis every other day if obtainable, which was usually for the first 3-7 days. Cats presenting with dyspnea were examined by thoracic ultrasonography and a fluid sample obtained by ultrasound-guided paracentesis. Effusions were examined for presence of fibrinous precipitates, an admixture of neutrophils and small/large mononuclear cells, intensity of yellow discoloration, viscosity by threading and total protein content. Cell pellets from peritoneal or thoracic effusions were also examined by qRT-PCR for viral RNA levels as previously described. 6 Cats were discharged to their owners when a positive response to treatment was noted, usually within 5 days. The owner(s) were instructed either by the trial veterinarian or primary-care veterinarian on how to administer the medication twice a day by subcutaneous injection. Injection sites were varied to include the topline from the nape to the mid-back and on the sides of the chest and flanks. Care was taken to avoid depositing drug into the dermis or sequentially at the same subcutaneous site. Owners were encouraged to keep daily logs on rectal temperature, activity, appetite, defecation and urination, and weekly to bi-weekly body weights. Periodic blood samples for CBC and serum chemistry values were obtained by the owners' personal veterinarians and sent to commercial veterinary diagnostic laboratories. Any abnormal signs or behaviors were to be noted and promptly reported. Euthanasia, when required, was conducted either at UC Davis or by the primary-care veterinarian. Bodies of cats euthanized by primary-care veterinarians were immediately refrigerated and sent on ice packs by overnight express mail to UC Davis for necropsy. The owners' request for care and final disposition of the body was honored.