Infrequent detection of papillomaviral DNA within canine cutaneous squamous cell carcinomas, haemangiosarcomas and healthy skin on the ventrum of dogs

BACKGROUND: Canine squamous cell carcinomas (SCCs) most frequently develop on the ventral abdomen and are thought to be caused by ultraviolet (UV) light. Papillomaviruses (PVs) have been associated with cutaneous SCCs in multiple species, including dogs. HYPOTHESIS: That PVs act as cofactors in canine UV-induced SCCs. ANIMALS: The study was performed on skin from the ventrum of 60 dogs. These samples included 20 SCCs, 20 haemangiosarcomas and 20 samples of clinically normal skin. Two canine viral plaques were included as positive controls for PV. METHODS: PCR was used to amplify PV DNA from all samples. Primers used included two sets of consensus primers and two sets of primers that were designed specifically to amplify PV DNA sequences detected in the viral plaques. RESULTS: The MY09/11 consensus primers amplified PV DNA from both viral plaques. One plaque contained a DNA sequence (CfPV-JM) that had been previously reported from a dog with multiple cutaneous SCCs. The other plaque contained a previously unreported PV DNA sequence. No PV DNA was amplified by either consensus primer from any of the ventrum skin samples. Primers designed specifically to amplify the CfPV-JM sequence amplified DNA from one SCC, but no other sample. No PV DNA was amplified using the other specific PCR primer set. CONCLUSIONS AND CLINICAL IMPORTANCE: These results do not support a significant role for PVs in SCC development from the ventrum of dogs. However, they contribute another PV sequence to the list of PVs that have been associated with viral plaque development in dogs.