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 disorders, the epidemiology and pathogenic role of BHV‐4 in cats is unknown. The purpose 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 peripheral blood leukocyte samples were collected from 52 male and 52 female free‐roaming cats impounded at a regional animal control facility in Central Michigan. Plasma concentrations of BHV‐4 antibodies were measured with an indirect fluorescent antibody test. Peripheral blood leukocyte DNA was isolated, and a 2‐stage polymerase chain reaction with heminested primers delineating 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 significantly more likely to be male than female (odds ratio = 3.22; P= .007). Cell‐associated viremia was detected in 17 (33%) male and 11 (21%) female cats. Of the 61 seropositive cats, 23 (38%) had a detectable viremia; only 5 (12%) seronegative cats had detectable viremia. Seropositive cats were significantly more likely to be viremic than sero‐negative cats (OR = 4.30; P= .009). Our results suggest that BHV‐4 infection may be more widespread in certain cat populations than previously reported. Furthermore, many cats seropositive for BHV‐4 antibodies have a concurrent cell‐associated viremia.