Efficacy and safety of the nucleoside analog GS-441524 for treatment of cats with naturally occurring feline infectious peritonitis

Pedersen, Niels C; Perron, Michel; Bannasch, Michael; Montgomery, Elizabeth; Murakami, Eisuke; Liepnieks, Molly; Liu, Hongwei

One cat in the study (CT80) had confounding clinical signs. Although the cat presented with effusive abdominal FIP, it also had long-standing signs of vague hindlimb lameness, lower back pain, periodic bouts of falling, reluctance to jump to higher places, and unexplainable and transient changes in behavior. These signs prompted the cat to be treated for a long time after the abdominal effusion disappeared. A decision was ultimately made to discontinue treatment and see if more characteristic FIP signs would recur. The cat was ultimately euthanized and found to have congenital-type HCM and no residual lesions of FIP or viral RNA in any tissues upon necropsy. Dilated cardiomyopathy has been reported in 17.6% of HIV-infected people on chronic antiretroviral therapy. 23 It was concluded, however, that GS-441524 was not the cause of the heart disease in this cat. Heart disease in this cat was hypertrophic rather than the dilative form seen in patients with HIV, and HCM is a common condition among shelter cats. 24