Equine and bovine papillomaviruses from Turkish brood horses: a molecular identification and immunohistochemical study

Papillomaviruses have an oncogenic nature, developing benign or malignant tumours in association with the proliferation of cutaneous or mucosal epithelia in humans and animals. The objective of this study was to investigate, the genoprevalence of bovine papillomavirus (BPV) types 1 and -2. and equine papillomavirus (EcPV) types 1. 2 and 3 in Turkish brood horses, with or without genital lesions and skin tumours. and confirmation of the equine sarcoids by several immunohistochemical markers. A total of 42 genital swabs and 6 skin tumours were collected from Thoroughbred stallions/mares in Turkey. Overall, both EcPV and BPV specific DNA amplicons sampled were detected in genital swabs from 38.1% of the brood horses tested by PCR. The prevalence of BPV-1, BPV-2 and EcPV-2 in the Turkish brood horses was 14.3%, 2.4% and 21.4%, respectively. Furthermore, there was no significant difference between the horses that appeared to be healthy (38.7%) and symptomatic horses (36.4%) (P>0.05). Out of the six samples obtained from the six horses that had skin tumours, BPV-1 was detected in five tissue samples and four blood samples, and only one skin tumour was found to be infected with EcPV-2. This study indicates that a high prevalence of EcPV-2 and BPV-1 was found in apparently healthy horses as well as in symptomatic cases. Additionally, the horses infected subclinically with papillomaviruses may play a significant role in the epizootiology of papillomavirus infections and lead to an increase in reproductive problems in brood horse populations.