Investigation into Equine Papillomavirus Type 2 Prevalence and Diagnosis

Abstract

Equine papillomavirus type 2 (EcPV-2) has been consistently associated with most equine genital cancers and a subset of cancers at other locations. The prevalence of EcPV-2 in healthy horses has been estimated to be <20% for DNA presence, and 10-36% for anti-EcPV-2-L1 seroprevalence. However, no study has thus far examined the prevalence of EcPV-2 at the herd-level or over multiple timepoints. This thesis examined EcPV-2 prevalence in a predominantly closed herd with a known EcPV-2 infected horse over three timepoints. We found that DNA prevalence (0-4%) was equivalent to the general horse population, but that seroprevalence (51.5%) was higher. Additionally, no study has examined the distribution of EcPV-2 infection in situ, nor compared such a technique to PCR. We found that RNA ISH concorded with PCR in 80% of cases. We also recapitulated previous results concerning EcPV-2 distribution in situ as well as found EcPV-2 in numerous novel locations.