Feline Coronavirus (FCoV)
Feline coronavirus (FCoV) belongs in the family Coronaviridae, together with canine coronavirus (CCoV). Two biological types of FCoVs are known: feline infectious peritonitis virus (FIPV) and feline enteric coronavirus (FECV). In the widely accepted “in vivo mutation” theory, FIPV arises by mutation from parental FECV in the gastrointestinal tract of an infected cat, spreads systemically and causes feline infectious peritonitis (FIP).
FCoV strains can be classified into serotypes I and II. FCoV serotype I strains are wholly feline and cause a slowly developing cytopathic effect. FCoV serotype II strains seem to have arisen by recombination between FCoV serotype I and CCoV. They induce a lytic cytopathic effect.
Sample: Rectal swab, CSF, Ascites
Modes of transmission
FCoVs spreads predominantly by the fecal-oral route.
FECV infections are usually associated with mild disease at most. Many cases remain asymptomatic, and in young kittens mild transient diarrhea of several days duration is generally the only sign. Vomiting occurs in a smaller proportion of cases and is not usually a prominent feature. FIPV variants of FCoV cause fatal peritonitis, „wet“, more severe form, or „dry“ form of disease. „Wet” form of disease is characterized by leakage of protein-rich fluid from the blood vessels into the peritoneal, pleural and pericardial cavity. The typical lesions are pyogranuloma and fibrinous plaques on the serosal surfaces of abdominal organs. Anorexia, dyspnea, mild pyrexia, and muffled heart sounds are common. Radiographs can reveal hepatomegaly or renomegaly. In „dry“ form of the disease granulomas usually appear in eyes and CNS, but can also be found in peritoneal cavity.
Therapy and prognosis
There is no curative treatment for FIP, the treatment is based on facilitating the symptoms. If cats develop the „wet“ form of the disease they die in first two months after the infection. If they develop the „dry“ form they can live up to few months. Reported mortality in catteries and multi-cat households ranges from 17.3 to 29.4%.
There is no available vaccination for FCoVs in Croatia. Separating infected cats from the healthy ones is important in prevention of spreading the infection.
FCoV infection is extremely common in cat populations. Antibodies against FCoV are found in 20%–60% of pet cats and up to 100% of cats in catteries or multi-cat households. Type I FCoV is predominant in the field, whereas type II virus represents only 2-30% of infection.
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Wang, Y.-T., Su, B.-L., Hsieh, L.-E., and Chueh, L.-L. (2013). An outbreak of feline infectious peritonitis in a Taiwanese shelter: epidemiologic and molecular evidence for horizontal transmission of a novel type II feline coronavirus. Vet Res 44, 57.