Feline infectious peritonitis (FIP) is a major killer of pedigree/purebred kittens and cats from rescue shelters in the 21st century. FIP is one of the most enigmatic, and difficult to diagnose, feline diseases. FIP is caused by feline coronavirus (FCoV), but most cats infected with FCoV do not develop FIP. The key messages of this book are: 1.The most important way to prevent FIP is by preventing infection with feline coronavirus. 2.Have any new kitten or cat tested for FCoV antibodies before bringing him or her into your home, if you already have cats. 3.Most cats infected with FCoV eliminate the virus after a few months, and remain perfectly healthy. 4.Cats become infected with FCoV by contact with cat litter (or cat litter dust particles) contaminated with virus laden faeces from an infected cat. 5.Most cats suspected of having FIP actually have some other, often treatable, condition.