SOCK it to FIP

FIP is caused by a feline coronavirus. Coronaviruses of various species exist in most types of animals and humans and usually cause acute respiratory or enteric disease. FIP is the cause of death of 1 in 100 to 1 in 300 cats in U.S. The incidence can be 5 or more times greater among young cats coming from catteries and shelters and is the major cause of abdominal fluid (ascites) and intraocular and neurologic inflammatory disease in cats under 3-5 years of age. FIP is virtually 100% fatal and there is no good prevention. The emotional toll of FIP is especially great, because it strikes suddenly weeks, months and even years after initial infection. Therefore, cat lovers usually experience this disease long after they have developed strong emotional bonds with their new pet.

Coronviruses are ubiquitous among all cat populations and the principle one of cats is correctly referred to as feline enteric coronavirus (FECV). FECV is present in virtually all catteries with 6-8 or more cats and up to 40% or so of the kittens relinquished to shelters. The enteric virus in the cat population lives in the digestive tract and is shed in feces. Cats can shed the virus for 4-6 months or for a year or more in a continuous or intermittent fashion. Recurrent infections are also common. FECV is readily spread through litter and litter dust, and can be carried from place to place on people's bodies and clothing. Virus contaminated material is easily transferred to the paws and fur of susceptible cats and then ingested during grooming. Kittens are infected by other cats at about 9-10 weeks of age, although one report places it as early as 3 weeks.

FIP is caused by a mutation of FECV. Although the mutation of FECV to FIPV is common, it is fortunate that only a small percentage of cats exposed to this mutant virus will get FIP.  FECV is undergoing continuous mutation and several genetic forms of the virus may co-exist in the same animal at the same time. Most of these mutations have very little effect on the behavior of the virus and merely serve to genetically reflect the region from which the virus originated. However, certain have a pronounced effect on the biologic behavior of the virus One study indicated that 20% of the kittens infected with FECV will produce an FIP mutant. Of course, only a fraction of the mutants will go on to produce FIP, depending on host resistance factors (genetic or non-genetic).

FIP was first recognized as a specific clinical entity in the late 1950's. This timeline was based on decades of meticulous necropsy records kept by pathologists at the Angell Memorial Animal Hospital. There was a steady increase in the incidence of the disease in the 1960's onward, and it is currently one of the leading infectious causes of death among young cats from shelters and catteries.

FIP affects both pure- and random-bred cats. However, the disease usually starts in young kittens so it is closely linked with cat breeding and sheltering. The disease is also enhanced by improper husbandry, especially resulting from overcrowding (shelters, large multiple cat households). We also know that genetic susceptibility may account for 50% or more of the risk of developing FIP in one pure breed that was studied.

The age of the cat at the time of initial FECV exposure may play an important role in whether a cat dies from FIP. Kittens usually began shedding FECV at around 9-10 weeks of age, which places their actual exposure a few days to a week earlier. The immune system of the kitten is rapidly maturing during the period between 6-16 weeks of age. Therefore, the first exposure of most cats to FIP causing mutants occurs during a time period when their immune systems are still developing. This lack of development enhances the likelihood of a FIPV mutant to gain a strong foothold into the body. Just as there is an age susceptibility, there also appears to be an age resistance. FIP is seldom seen in cats over 3-5 years of age, and most cases occur before 16 months of age.

Anything that stresses cats can depress immunity and also increase the likelihood that FIPV will establish itself in the body. Stress may also allow an FIPV that is being successfully contained to become active. The effect is even more powerful if the stress occurs at or shortly after the time the cat is exposed to the virus. Stressors can include overcrowding, weaning, spaying or neutering, other infections, being placed in a new and strange household, adding new cats to a household, shipping cats to new owners or other catteries, or stresses of pregnancy, parturition and lactation. Disease caused by feline herpes virus and other common upper respiratory pathogens are good indicators of cattery or shelter stresses.

Signs of FIP arise weeks, months, and in rare cases years after initial infection. During this quiescent stage, the cat may be asymptomatic or suffer from vague signs such as stunted growth or increased susceptibility to other common infections. Many believe that FIP can cause upper respiratory disease signs during its early stages; this is not technically correct, because upper respiratory disease is usually caused by herpesvirus, chlamydophilla, mycoplasma, etc., and not directly by FIPV.

Cats with FIP do not appear to be very contagious to cats that they come in contact with. Although this has been based mainly on clinical observations, it has also been confirmed by laboratory studies. Contact transmission has not been observed in experimental settings. Furthermore, cat-to-cat transmission implies that every FIPV isolated from a group outbreak of FIP will be genetically identical. UC Davis researchers have yet to observe this. However, researchers now know that FIPV is present in the feces of some cats with FIP, so horizontal transmission is theoretically possible, and may explain the uncommon epizootics of FIP where a number of cats in the same environment develop FIP within a days or weeks of each other.

There is no single definitive test for FIP at this time, however the diagnosis of FIP should be relatively simple given its affinity for younger cats, its strong tendency to involve catteries and shelters, the typical physical and historical findings, and numerous characteristic laboratory abnormalities. Nonetheless, it remains one of the most difficult of diagnoses for many veterinarians. The truth is that veterinarians have little trouble in placing FIP high, or at the top, of their diagnostic list, but have great difficulty, and even reluctance, in confirming their diagnosis. This is probably because FIP is viewed as a death sentence, and they are reluctant to confer such a sentence without certain proof.

There is currently no cure for FIP; therefore, the primary concern needs to be making the cat comfortable and deciding when to quit. Cortisone can help reduce inflammation and encourage appetite. Good nutrition, hydration and non-stressful environments are also important, but in almost all cases they serve only to prolong the inevitable. Therefore, we will encourage some owners to go with symptomatic treatment, but only if the animals are not suffering. Owners of cats with FIP should be wary of claims for alternative type therapies that are based on anecdotal evidence.

There have been reports that the feline interferon omega is effective in combating FIP. Davis researchers actually tested it against FIP years ago and it did not work. Fortunately, a double blind, placebo controlled study was recently reported from Europe on the use of interferon omega in treating FIP. Cats receiving this very expensive treatment fared no differently than placebo treated cats.

This is a decision only the cat's owner can make, and it is a difficult one. It is not recommended to euthanize a cat, even with FIP, as long as it looks and acts fairly normal. Miracles do happen, but they can't happen unless they are provided time to happen. However, some owners choose to end suffering at an earlier stage, given the grave prognosis. Many owners decide to put an animal down when it no longer takes pleasure in life. But cats can feign health to the last. There is a myth that if a cat is still purring it is still enjoying life. Research has shown, however, that cats purr even when in extreme pain, it is another way that they mask illness.

If you have lost a cat to FIP, remove any cat related items that you cannot wash or disinfect, such as a scratching post or soft toys. Clean and disinfect everything else in the environment that you can. Time will take care of the rest, because viruses of this type are not long-lived in the environment. A couple of months are recommended, which is standard for most infectious diseases.

A vaccine has been developed and is available. However, it has to be used in kittens at least 16 weeks of age (most cats are already exposed to coronavirus at this age), it is not effective in cats already exposed to coronavirus (which is most cats), it is not effective against the common serotype of FIPV, and even when all factors are optimal, it has low efficacy. In short, it does not work in the environments where it is needed most (catteries and shelters) and is not justified in older pet cats where FIP is hardly seen. UC Davis researchers do not recommend its use.

Avoid stress and overcrowding. Keep cats in small, separate groups. Consider isolating kittens from a mother cat at weaning to avoid exposure to the virus. Don't mix very young kittens with older kittens. If you can limit coronavirus exposure until 12-16 weeks of age, when the immune system is better developed, the likelihood of developing FIP may be lessened. Breeders should avoid matings between cats who have had close relatives that have died of FIP or who have produced kittens that developed FIP. Also follow accepted protocols for vaccinations and practice good husbandry to limit other infections. Clean and disinfect cages and litter boxes regularly. The corona virus is easily killed by bleach and other disinfectants.

It is true that there is currently no cure, or totally effective prevention. But researchers understand the virus and the infection much better now. They have new tools that allow them to look at viruses at the molecular level. Any knowledge about the virus and how the host cat responds to it will have influence down the road. The Feline Genome has been sequenced, and with this important new feline DNA roadmap researchers will be able to identify viral genes responsible for causing disease (which will facilitate antiviral drug development) and host genes that confer resistance/susceptibility (which will facilitate genetic control).

All funds given to SOCK FIP for the CCAH will go right into FIP research. Some of this research will be clinical in nature, and some bench top. $50,000 - 75,000 a year supports a single technician or graduate student, and the more such people the CCAH can engage in research the faster we will reach our goals. The genetic testing will be expensive - the DNA chip arrays will cost $400 or more each just to purchase (once they are developed by commercial companies), read, and analyze. As demonstrated by SOCK FIP's predecessor, SOCK it to Leukemia, a great deal of money can be raised by ordinary people), and a lot can be accomplished with that money if it is concentrated in the hands of knowledgeable and capable researchers.

Though SOCK FIP is trying to focus funding on U.C. Davis for greater impact, the scientific community is very collaborative and pedigree/disease information and DNA samples will be useful for meaningful collaborations. UC Davis researchers are also aware that other groups are raising money to study FIP, and this is also respected and accepted. The goal of SOCK FIP and the UC Davis Center for Companion Animal Research is to solve FIP and in the end it really does not matter how it is accomplished or who does it. Scientific competition is always good. A world full of researchers have studied this disease for over 40 years, and although we know a lot more about it, we still do not have effective ways to totally prevent or cure this disease. Hopefully, this worldwide research effort will finally bear the needed fruit. Researchers at UC Davis and the CCAH can only do the best as their part.