Canine parvovirus is shed infrequently by cats without diarrhoea in multi-cat environments

Whether subclinical shedding of canine parvovirus (CPV) by cats might contribute to the epidemiology of canine CPV infections, particularly in facilities housing both cats and dogs, requires clarification. Conflicting results are reported to date. Using conventional PCR (cPCR) to amplify the VP2 gene, shedding of the CPV variants (CPV-2a, 2b, 2c) by healthy cats in multi-cat environments was reportedly common in Europe but rare in Australia. The aim of this study was to determine whether low-level faecal CPV shedding occurs in multi-cat environments in Australia and Italy using a TaqMan real-time PCR to detect Carnivore protoparvovirus 1 (CPV and feline parvovirus, FPV) DNA, and minor-groove binder probe real-time PCR assay to differentiate FPV and CPV types and to characterize CPV variants. In total, 741 non-diarrhoeic faecal samples from shelters in Australia (n = 263) and from shelters or cat colonies in Italy (n = 478) were tested. Overall, Carnivore protoparvovirus 1 DNA was detected in 49 of 741 (6.61 %) samples. Differentiation was possible for 31 positive samples. FPV was most common among positive samples (28/31, 90.3 %). CPV was detected in 4/31 samples (12.9 %) including CPV-2a in one sample, CPV-2b in another and co-infections of FPV/CPV-2b and CPV-2a/CPV-2b in the remaining two samples. A high rate of subclinical FPV infection was detected in one shelter during an outbreak of feline panleukopenia, during which 21 of 22 asymptomatic cats (95.5 %) sampled were shedding FPV. Faecal shedding of CPV by cats in multi-cat environments is uncommon suggesting that domestic cats are not significant reservoirs of CPV.