This article is published in this site with the special permission of END FIP®
FCoV is common in places where a large group of cats is housed together indoors (i.e., breeding catteries, animal shelters, rescue organizations, etc.). The virus is shed in feces and cats become infected by ingesting or inhaling the virus, usually by sharing cat litter trays or by the use of contaminated litter scoop or brushes transmitting infected microscopic cat litter particles to uninfected kittens and cats. [Ref. 4] Transmission is mainly indirect, rarely direct and NOT trans-placental.
In young kittens, FCoV infection occurs after maternal antibodies diminished at around six weeks of age and when the kittens are raised in contact with the litter trays of virus-excreting adult cats. Crowded conditions as those found in most purebred catteries, shelters and some multi-cat households increases risk of infection (ranging from 50% to 90%) whereas the prevalence of FCoV infection in free roaming feral and strays cats is much lower (estimated at about 15%) due to less exposure to fecally excreted virus than indoor housed cats.
FCoV is quite a fragile virus which usually is inactivated within 48 hours at room temperature; however, the virus can survive up to seven weeks in dried fecal matter thus small particles of used litter are an important source of infection in the environment. Contaminated surfaces, dishes, human clothing, shoes, and hands can act as fomites thus following detailed husbandry strategies are a must. A mixture of household bleach and hot water (at a dilution of 1:32) or other feline friendly disinfectants, easily destroys FCoV.
While FCoV is ubiquitous in cats worldwide, fortunately, the vast majority of cats infected with FCoV do NOT develop FIP, but become infected, shed virus on their feces from 2-3 days post-infection, seroconvert at 18-21 days, stop shedding the virus after 2-3 months to 7 months, then lose their antibodies. About 13% of infected cats become lifelong carriers, continually shedding FCoV in their feces and maintaining a high antibody titer. Natural immunity to FCoV is poorly understood but is presumed to be cell mediated rather than antibody mediated.