A vaccine is commercially available for vaccinating healthy cats against FIP. Mired in controversy since its introduction a decade ago, this vaccine was considered ineffective at best and potentially disease-causing at worst. Recent studies suggest that the FIP vaccine does not cause illness in cats, but experts still debate its effectiveness in preventing disease. Because FIP is not a purely infectious disease in the strict sense, understanding it and preventing it presents complex problems not seen with diseases like herpes virus infection and panleukopenia. I am strongly against over-vaccination of my patients, and I require very convincing evidence of a vaccine’s safety and effectiveness before I will use it in my feline practice. I do not routinely recommend vaccination of kittens and cats with the currently available vaccine.
Recently, scientists at the University of California—Davis have shown that there is a probable genetic component to feline infectious peritonitis. That is, a cat’s genes may well make it more or less likely to contract this disease. This finding is an important one, but not at all surprising. We know that most cats that become infected with the GI coronavirus do not ultimately develop FIP. We also know that it does not spread “horizontally” to any great degree.
That is, it is not transmitted from sick cats to healthy cats the way most other infectious diseases are. While the GI coronavirus does pass from cat to cat, usually via contact with virus-contaminated feces, the fatal FIP virus does not appear to do this to an extent. Instead, some as the yet unknown trigger in only some cats allow or causes the GI coronavirus to transform into the pathogenic FIP virus, invade the cat, and wreak havoc.
For many observers of this enigmatic disease, including myself, it has seemed clear for some time that an individual cat’s unique genetic makeup must play an important role in this uncertain and unpredictable outcome. Further, we know that the cat’s own immune surveillance and attack system is a crucial element in the damage done during this disease. The reactivity of this system is genetically programmed, like all other aspects of the body’s function. It should come as no surprise, then, that certain cats would have innate susceptibility or resistance to this terrible feline plague.
If this is the case, then, scientists may be able to study families of highly susceptible cats in an attempt to better understand the nature of FIP. Perhaps such studies will yield answers about how to design well early diagnostic tests, maybe even DNA tests that would allow veterinarians to check young kittens for susceptibility long before they become ill. Research with genetically susceptible families of cats could even yield clues about effective treatments, and better preventive tools. Like all feline disease research, studies into the nature of FIP are seriously under-funded because there are no government subsidies for this work. However, many organizations currently solicit public donations to provide research grants to scientists who study FIP.