FIP is a problem of cats kept in groups, particularly in breeding catteries and in rescue situations. Since the most important route of transmission is fecal-oral transmission, Hygiene is the foremost method of FIP control in any multi-cat environment. FCoV infection is maintained in a household or cattery by continual cycles of infection and re-infection [Foley et al, 1997, Addie et al, 2003] with the source of infection being the cat litter tray. FIP is rarely a problem amongst cats leading a natural, indoor-outdoor, lifestyle. The goal in every cat household has to be to reduce the FCoV pressure and risk of transmission. This can be done by avoiding large numbers of cats in single households, keeping small group groups of cats of not more than 3 (well-adapted) cats per room, observing strict hygiene, and providing outdoor access to enable the cats to bury their faeces. If the latter is not possible, enough litter boxes should be provided, cat litter boxes have to be cleaned frequently, and litter trays should be in different rooms from food bowls.
Breeding catteries are high-risk situations for FIP. Today, in most European countries, there are few catteries in which FCoV is not endemic. In some catteries, attempts have been made to control the spread of FCoV by segregation. A policy of separating cats which are shedding high amounts of FCoV from low shedders and negative cats has been suggested for reducing transmission within a cattery but the value of this approach is controversial. High shedders can be detected using RT-PCR screening of faeces but multiple sampling (optimum 4 times over 3 weeks) may be necessary for this to be reliable and this presents practical difficulties. Virus shedding occurs over several months is life-long , in some cats, especially in multi-cat households.
Kittens typically develop FIP in the post-weaning period [Cave et al, 2002], therefore many breeders are unaware that they have endemic FCoV infection, since FIP deaths usually occur once the kittens are in the new household. Most kittens are protected from FCoV infection by maternally derived antibodies until they are between 5 and 6 weeks of age. It has been reported that it may be possible to prevent FCoV infection of young kittens by isolating pregnant queens 2 weeks before birth and removing kittens from their mother to a clean environment when they are 5-6 weeks old and maintaining them there until they go to a new home [Addie & Jarrett, 1990, 1992 and 1995]. For this technique to work, the breeder is required to strictly follow strong hygiene methods. However, controversy exists about the efficacy of this method.
Although documented in rare cases, transplacental transmission of FCoV does not appear to be a problem [Addie & Toth, 1993].
Chalmydophila can be a significant cause of disease in rescue shelters but is generally a less significant problem than respiratory viruses. Vaccination should be considered if there has been a previous history of Chlamydial disease in the shelter. Since close contact is necessary for transmission and the organism has MGP: low viability outside the host, single housing of cats and routine hygiene measures should avoid cross infection. Whenever cats are maintained together longer term, they should be vaccinated regularly.
Strict hygiene precautions should be enforced at all times to attempt to minimise viral spread and to keep virus load at a minimum. Ideally, cats should be kept separately. New catteries should be designed with infectious disease control and stress reduction as a priority.
Vaccination of a cat that is unlikely to have been exposed to FCoV, and is entering a boarding or rescue cattery may be considered.