Identification of Pseudocowpox Virus in Angus Bull with Failure to Breed

Pseudocowpox, a Parapoxvirus, causes a common mild infection of the udder and teats of cows. Infection of genital organs has not been reported before in bulls. In this report, pseudocowpox virus (PCPV) was identified from one of two 1-year-old Angus bulls (Bos taurus) with red rashes and papule lesions on the surface of the penis. Inoculation of bovine turbinate cells or primary bovine testicular cells with the swab of the papule lesions produced CPE characteristic of pox virus infection. Parapoxvirus like particles were observed by EM in viral pellets of the tissue culture isolate. To confirm the virus, designated 14V10296 isolate, was a Parapoxvirus, viral DNA of the 14V10296 isolate was examined by PCR with pan Parapoxvirus primer sets that could amplify B2L gene of all four Parapoxviruses. The expected B2L amplicons of the 14V10296 isolate showed 99% homology to B2L of PCPV strain F00.120R. To further confirm the isolated virus is PCPV, PCR primers specific for Orf vascular endothelial growth factor gene and IL-10 and PCPV uracil DNA glycosidase (UDG) and IL-10, respectively, were used to amplify the viral DNA of the 14V10296 isolate. Only when PCR primers specific to PCPV UDG and IL-10 were used, expected products were amplified from viral DNA of the 14V10296 isolate, respectively. Phylogenetic analysis suggests the 14V10296 isolate is closely related to PCPV strain F00.120R, an isolate from reindeer. These results from tissue culture, EM, PCR amplification and DNA sequence analysis suggest that the bulls were infected by a PCPV which is closely related to PCPV strain F00.120R.