A serological study of canine herpesvirus-1 infection in a population of breeding bitches in Norway

Abstract

BackgroundCanine herpesvirus-1 (CHV1) causes a fatal hemorrhagic disease in neonatal puppies and is associated with infertility in female dogs. This study was conducted to assess the status of CHV1 infection in bitches in proestrus or estrus and to investigate possible risk factors by a detailed questionnaire. Blood samples were collected from healthy bitches (n = 193) not vaccinated against CHV1, aged one year or older and admitted for estrus control to the Canine Reproductive Clinical Unit, Norwegian School of Veterinary Science. The serum samples were analysed by immunoperoxidase monolayer assay and serum titers were recorded as the reciprocal value of the highest dilution producing specific cell staining.ResultsAltogether, 85.5% of the dogs had CHV1 titers ≥ 80 and were classified as positive. Mean age for dogs included in the study was 4.2 years (95% CI 4.0-4.5), and there was no difference in age between seronegative dogs vs seropositive dogs. When grouping the seropositive dogs into three categories according to the magnitude of the titer, a total of 38.8% of the bitches displayed a weakly positive titer of 80, 44.8% had moderately positive titers of 160 or 320 and 16.4% of the dogs fell into the strongly positive category with titer of ≥640. No association was demonstrated when comparing CHV1 antibody titers to fertility parameters such as previous matings, pregnancies, whelpings, puppies born or condition of puppies. Further, there was no difference in seroprevalence between bitches that had been abroad for a period of time and dogs only living within a Norwegian environment. Samples from dogs collected in summer and fall displayed moderate to high antibody titers indicating recent infection with CHV1. Season, previous birth, and participation in competitions/shows explained 67-78% of the variation in antibody titer.ConclusionsThis study demonstrates that CHV1 infection is common in breeding bitches in the eastern part of Norway. Associations with putative risk factors were not identified. However, season, previous whelping, and participation in competitions/shows explained 67-78% of the variation in antibody titer.

Prevalence of canid herpesvirus-1 infection in stillborn and dead neonatal puppies in Denmark

“…CaHV-1 infection was found in puppies originating from most areas of Denmark and puppies of different breeds were affected. Although it is difficult to extrapolate from a study based on examination of 57 dead puppies from 37 litters to the Danish dog population in general, these findings still indicate that CaHV-1 occurs widely in the Danish dog population similarly as previously reported from other North European dog populations [ 14 - 18 ]. The overall prevalence of CaHV-1 infection in this study was 22.8%, but it varied between age groups.…”

“…Other studies have identified bacterial infections and fetal asphyxia as the main causes of puppy mortality [ 11 , 12 ]. Reports of fatal neonatal CaHV-1 infections have been published [ 13 , 14 ] and even though serological studies from many European countries indicate that CaHV-1 infection is widespread in adult dogs, with antibody prevalence ranging from 40-88% [ 14 - 18 ] CaHV-1 is not considered to be a major cause of mortality in puppies [ 10 - 12 ]. However, information on the prevalence of CaHV-1 infection in neonatal dogs is sparse.…”

Seroprevalence of Canine Herpesvirus-1 in Breeding Dogs with or Without Vaccination in Northwest Italy

“…The distribution of the titres that we found in our study suggests that the virus circulates in the kennels and that high titres may be a consequence of frequent reactivation and reinfection. Stress factors can reactivate a latent infection, and oestrus itself is a potential stressor: 85.5% of breeding bitches in proestrus or oestrus were classified as CHV-1 positive in a survey in Norway [12]. CHV-1 is considered to be poorly immunogenic, and antibodies raised against the virus after infection generally decline within a two-month period [6], although low titres can persist for up to eight months or longer [13].…”

The first molecular detection of Canine herpesvirus-1 in reproductive specimens of adult dogs in Iran

“…Dahlbom et al (2009) also reported 81.5% seroprevalence of CHV-1 in Finland [11]. Furthermore, the seroprevalence of CHV-1 infection was determined as 85.5% by immunoperoxidase monolayer assay (IPMA) in Norway [20]. Similarly, in a study performed in turkey in which virus neutralization test (VNT) and ELISA were used for investigation of CHV-1 seroprevalence, antibody against CHV-1 was detected in 39.3% of samples by ELISA in comparison to 29.4% of the specimens using VNT [21].…”