A review of feline infectious peritonitis virus infection: 1963–2008

F eline infectious peritonitis (FIP) was first described as an ‘important disorder of cats’ by Holzworth in 1963 at the Angell Memorial Animal Hospital, Boston and a clinico-pathologic conference on this disorder was published in the following year. The disease was thought to be infectious but no specific etiologic agent was identified at the time. Wolfe and Griesemer were the first to propose that FIP was caused by a virus. Zook et al observed virus particles in the tissues of experimentally infected cats, but were unable to characterize the agent. Ward recognized the close similarities of FIP virus (FIPV) in tissues to members of the family Coronaviridae. In 1972 Montali and Strandberg were the first to report that FIPV infection could be either granulomatous (dry, parenchymatous) or effusive (wet, non-parenchymatous). The close genetic relationship of FIPV to coronaviruses of dogs and swine was first reported by Pedersen et al in 1978. Fully virulent FIPV was first propagated in vitro in autochthonous macrophage cultures from experimentally infected cats and later in tissue culture. It was also replicated in the epithelium of intestinal ring cultures. A strain of FIPV (FIPV-UCD1) was first propagated in continuously passsaged Felis catus, whole fetus-4 (Fcwf-4) cells and shown to be virulent when inoculated into cats. The Fcwf-4 cells were later found to be of