Prevalence of bovine herpesvirus-4 infection in cats in central Michigan

The gammaherpesvirus bovine herpesvirus-4 (BHV-4) has been isolated from a wide variety of animals, including lions and domestic cats. Although BHV-4 antibodies have been detected in normal cats and cats with urinary disorder s, the epidemiology and pathogenic role of BHV-4 in cats is unknown. The pu rpose of this study was to determine the prevalence of BHV-4 antibodies and viral nucleic acid in a population of free-roaming cats. Plasma and periph eral blood leukocyte samples were collected from 52 male and 52 female free -roaming cats impounded at a regional animal control facility in Central Mi chigan. Plasma concentrations of BHV-4 antibodies were measured with an ind irect fluorescent antibody test. Peripheral blood leukocyte DNA was isolate d, and a 2-stage polymerase chain reaction with heminested primers delineat ing a conserved portion of the BHV-4 glycoprotein B gene homologue was used to amplify BHV-4-specific DNA sequences. BHV-4 antibodies were detected in 38 (73%) male and 23 (44%) female cats. Seropositive cats were significant ly more likely to be male than female (odds ratio = 3.22; P = .007). Cell-a ssociated viremia was detected in 17 (33%) male and 11 (21%) female cats. O f the 61 seropositive cats, 23 (38%) had a detectable viremia; only 5 (12%) seronegative cats had detectable viremia. Seropositive cats were significa ntly more likely to be viremic than seronegative cats (OR = 4.30; P = .009) . Our results suggest that BHV-4 infection may be more widespread in certai n cat populations than previously reported. Furthermore, many cats seroposi tive for BHV-4 antibodies have a concurrent cell-associated viremia.