Feline calicivirus and other respiratory pathogens in cats with Feline calicivirus-related symptoms and in clinically healthy cats in Switzerland

Abstract

BackgroundCats with feline calicivirus (FCV)-related symptoms are commonly presented to veterinary practitioners. Various clinical manifestations have been attributed to FCV, i.e. upper respiratory tract disease (URTD), oral ulcerations, gingivostomatitis, limping syndrome and virulent systemic disease. Additionally, healthy cats can shed FCV. The aims of this study were 1) to investigate the frequency of FCV in cats with FCV-related symptoms and in healthy cats in Switzerland, 2) to assess risk and protective factors for infection, such as signalment, housing conditions, vaccination, and co-infection with URTD-associated pathogens, and 3) to address the association between clinical symptoms and FCV infection.ResultsOropharyngeal, nasal and conjunctival swabs were collected in 24 veterinary practices from 200 FCV-suspect and 100 healthy cats originating from 19 cantons of Switzerland. The samples were tested for FCV using virus isolation and reverse-transcription real-time quantitative polymerase chain reaction (qPCR) and for feline herpesvirus-1 (FHV-1), Mycoplasma felis, Chlamydophila felis, Bordetella bronchiseptica using real-time qPCR. Within the two populations (FCV-suspect/healthy), the observed PCR prevalences were: FCV 45 %/8 %, FHV-1 20 %/9 %, C. felis 8 %/1 %, B. bronchiseptica 4 %/2 %, M. felis 47 %/31 % and any co-infections thereof 40 %/14 %. Based on multivariable regression models amongst FCV-suspect cats (odds ratio [95 % confidence interval]), co-infection with M. felis (1.75 [0.97; 3.14]), group housing (2.11 [1.02; 4.34]) and intact reproductive status (1.80 [0.99; 3.28]) were found to be risk factors for FCV infection. In healthy cats, intact reproductive status (22.2 [1.85; 266.7]) and group housing (46.4 [5.70; 377.7]) were found to be associated with FCV infection. Based on an univariable approach, FCV-suspect cats were found to be significantly less often FCV-positive when vaccinated (0.48 [0.24; 0.94]). Oral ulcerations, salivation, gingivitis and stomatitis, but not classical signs of URTD were significantly associated with FCV infection (all p < 0.001).ConclusionsFCV was detected in less than half of the cats that were judged FCV-suspect by veterinary practitioners. For a clinical diagnosis, FCV-related symptoms should be revisited. FCV infection was present in some healthy cats, underlining the importance of asymptomatic carriers in FCV epidemiology. To reduce FCV-related problems in multi-cat environments, reduction of group size in addition to the generally recommended vaccination are advocated.Electronic supplementary materialThe online version of this article (doi:10.1186/s12917-015-0595-2) contains supplementary material, which is available to authorized users.

Correlation between clinical signs of feline conjunctivitis and molecular detection of felid herpesvirus-1, feline calicivirus, chlamydophila felis and mycoplasma felis in cats from shelters in Rio de Janeiro

“…In relation to FCV, it has traditionally been considered as a minor primary conjunctival pathogen (MOCHIZUKI et al, 2000;GERRIETS et al, 2012;BERGER et al, 2015). In the present study it was observed in the same proportion as FHV-1, both in G1 and G2, in different scores, and it is possible that its role has been neglected.…”

“…In the present study it was observed in the same proportion as FHV-1, both in G1 and G2, in different scores, and it is possible that its role has been neglected. This observation underlines the importance of asymptomatic shedders in FCV epidemiology, as previously described by Berger et al (2015). FCV present high genetic variability (COYNE et al, 2006), which can be responsible for the observed diversity on the severity of clinical signs.…”

“…Therefore, it is possible to infer that, although not apparently capable of determining clinical conjunctivitis alone, these bacteria may play an important role complicating pre-existing infections as has been suggested by other authors (SYKES et al, 2001;HARTMANN et al, 2010). Our data suggest that, for clinical diagnosis of conjunctivitis by FHV-1, FCV, C.felis, and M.felis infections, symptoms overlap and therefore diagnosis has to be confirmed by molecular testing A high genetic variability is expected for FCV (ABD-ELDAIM et al, 2009;BERGER et al, 2015) and the specificity of the PCR primers may have been a limitation of the study.…”

“…The animals in the present study were housed together regardless of whether they were showing clinical signs or not. Living in a multi-cat household was, in fact, an important risk factor, as previously described (HELPS et al, 2005;BERGER et al, 2015). In the only shelter where cats were separated according to symptoms, there were no rules and sanitary barriers regarding the people who worked with these animals.…”

“…Particularly, Felid herpesvirus 1 (FHV-1) and Feline calicivirus (FCV) (BERGER et al, 2015), are responsible for the majority of the conjunctivitis cases (HARTLEY, 2010). Feline chlamydiosis (Chlamydophila felis) can be considered the main cause of bacterial conjunctivitis in kittens (HOLST et al, 2010;PŁONECZKA-JANECZKO et al, 2011).…”