The inheritance of susceptibility to feline infectious peritonitis in purebred catteries

Inheritance of susceptibility to feline infectious peritonitis was investigated with pedigree data from 10 generations of cats in purebred catteries. Cats that were first degree relatives of FIP-affected cats were significantly more likely to be affected by FIP than unrelated cats. It was often possible to trace inheritance of FIP in Persian catteries back to a particular ancestor. The mode of inheritance was best modeled as a polygenic trait. The heritabilities were very high: greater than 54% in four Persian catteries and 52% in one Birman cattery. Cat breeders might achieve success in reducing FIP risk by selecting cats from less susceptible lineages for their breeding programs.