Hi! I was wondering how common it was for cats to be carriers for feline coronavirus. I've read it can develop into FIP but how worrying would being a carrier be?
vet-and-wild here.
It depends a bit on the cat’s living situation. Catteries or other kinds of group housing more commonly have carriers. FeCoV generally only causes mild GI signs, but certain conditions can cause the virus to mutate and lead to FIP. So carrying the virus doesn’t necessarily mean a cat will get FIP. Theoretically any carrier is at risk, but the chance of developing FIP is still low. I found some statistics in my vet school notes:
Incidence of FIP in a 1-2 cat household: 1 in 5000
Percentage of FeCoV carriers is around 30% for household cats but 80-90% for catteries.
Immune function and genetics play a role in the development of FIP. Certain breeds may be predisposed as well. So yes, cats need to be infected with FeCoV to develop FIP, but just because they are infected it doesn’t mean they will develop it.