Feline herpesvirus 1 (FeHV-1) and feline calicivirus (FCV), associated with upper respiratory tract disease, are highly prevalent in cats worldwide. With the aim to investigate the importance of feline respiratory viruses in a heterogeneous population of cats, samples were taken in a rescue shelter in Liège, Belgium, between March 2005 and August 2006. Reverse transcription polymerase chain reaction (RT-PCR) and polymerase chain reaction (PCR) were performed to diagnose FCV and FeHV-1 infection in the sampled cats. The prevalence rate (33.1%) was higher for FCV than for FeHV-1 (20.1%) whereas prevalence rate of co-infection with both viruses was 10%. Gingivitis was more common in FCV infections (odds ratio (OR) ¼ 2.83) whereas respiratory signs were more often observed with FeHV-1 infections. The average age was significantly higher in FCV positive cats (38 months) than in FeHV-1 positive cats (29.9 months). The second and the fourth quarters of the year and the two first quarters were significantly more at risk than the others in the case of FeHV-1 and FCV infection, respectively. Age was found to be a confounding factor. High prevalence of both infections strengthens the importance of applying hygienic and preventive measures in rescue shelters where cats with an unknown status of vaccination are introduced.

Immuno-polymerase chain reaction (PCR) is an extremely sensitive detection method, combining the specificity of antibody detection and the sensitivity of PCR. We have developed an immuno-quantitative PCR (iqPCR), exploiting real-time PCR technology, in order to improve this immuno-detection method and make it quantitative. To illustrate the advantages of iqPCR, we have compared it with a conventional enzyme linked immuno sorbent assay (ELISA) technique in experiments aimed at detecting the cellular and the resistant form of prion protein in bovine brain extract. The iqPCR technique proved to be more sensitive than ELISA, so it could be a technique of choice for the diagnosis of infected animals both at an ante mortem and post-mortem stage.