Serological and virological detection of canine herpesvirus-1 in adult dogs with and without reproductive disorders

Canine herpesvirus 1 (CaHV-1) is known to cause reproductive disorders in adult dogs and neonatal mortality in puppies. The seroprevalence of CaHV-1 has not been documented in Italy. Sera from 865 dogs were screened for CaHV-1 using a serum neutralization assay (SN). All CaHV-1 positive sera and 100 CaHV-1 negative sera were also tested using an in-house immunofluorescence (IF) test. Thirteen bitches with reproductive disorders and three bitches with no history of reproductive diseases were also examined clinically so that lesions associated with CaHV-1 and CaHV-1 DNA could be identified using PCR analysis of vaginal swabs.An overall seroprevalence of 14.6% was observed using SN, and 18.6% using IF. The correlation between SN and IF was moderate. The SN assay demonstrated a greater sensitivity than IF, with a few exceptions. None of the vaginal swabs tested positive for CaHV-1 DNA. The differences in the seropositivity rates between SN and IF were not statistically significant (P = 0.16). Using the SN test as the reference standard, the sensitivity and specificity of IF were 29% and 95%, respectively. These results suggest that CaHV-1 is common in canine populations and could pose a threat to neonatal survival and canine fertility in breeding kennels in Italy. Vaccination of breeding bitches should be recommended if there is a history of reproductive disorders.