FIP was historically a fatal disease in cats. Breakthrough antiviral treatments have transformed the prognosis and welfare outlook for affected cats dramatically.
The transformation of FIP from a universally fatal diagnosis to a treatable disease represents one of the most dramatic welfare advances in veterinary medicine of recent decades. Cats with FIP previously faced a prognosis of weeks to months of progressive deterioration ending in death or euthanasia. GS-441524 and related antivirals change this completely: most cats treated during the active disease phase achieve sustained remission and return to full health. The treatment itself imposes welfare costs — daily injections cause discomfort and require sustained owner commitment — but the welfare benefit of survival and recovery vastly outweighs the treatment burden. The remaining challenge is equitable access: treatment cost remains high in many countries, creating welfare disparities based on owner financial capacity.