Bovine herpesvirus 4 DNA is not detected in free-ranging domestic cats from California, Colorado or Florida.

Objectives Several studies have reported that domestic cats can be naturally infected with bovine herpesvirus 4 (BHV4). Cats experimentally inoculated with BHV4 developed clinical signs involving the urinary tract, leading to the hypothesis that natural infection with BHV4 may be associated with feline lower urinary tract diseases. However, the question of whether BHV4 infection is common in cats remains equivocal. In this study, we sought to determine whether BHV4 is a common natural infection of domestic cats in the USA. Methods We used a sensitive nested PCR protocol specific to the BHV4 thymidine kinase gene to screen free-ranging domestic cat blood DNA samples (n = 101) collected from California, Colorado and Florida. Results Cats within this cohort were positive for seven other common pathogens of domestic cats, demonstrating the relatively high exposure of this population to endemic feline infections. In contrast, all domestic cat blood samples were negative for BHV4, while BHV4-containing tissue culture extracts were strongly positive. Conclusions and relevance BHV4 has been detected in tissues of latently infected cattle, though viral DNA is typically also detected in peripheral blood cells throughout infection. Our results suggest that persistent presence of BHV4 DNA in the blood of domestic cats is either rare or non-existent. We thus conclude that BHV4 is unlikely to be a major pathogen of cats.