Skin Pathology, Possibly Caused by Pox Virus, Leading to Severe Health Problems in Harbor Porpoises from European Waters
Two harbor porpoises admitted to the research and rescue centre of the Dolfinarium Harderwijk BV, Holland, and three harbor porpoises taken from pound nets into the Fjord and Belt Centre, Kerteminde, Denmark, developed skin lesions, possibly from pox virus, in captivity.
The lesions were varying in shape, color, and characters. They were found from the head to the tail and on the dorsal and ventral sides. In the three porpoises from the Fjord and Belt Centre the skin alterations appeared during the acclimatization time and were shown as mild to moderate lesions of the superficial epidermis. No changes in behavior were observed and lesions disappeared within 1 year. Contrary to the above situation, one of the rescued harbor porpoises from Harderwijk developed, after an initial improvement of its condition which included a near complete healing of its skin, pathologic skin lesions characterized by acute formation of bullae and pustules. The acute lesions would either develop into hard collagenous scar tissue or burst and form ulcers. The second rescued animal from Harderwijk had old circular lesions which seemed inactive. In January, it developed overnight pustular lesions on its mouth and tail stock.
Histologic, bacteriologic, mycologic, and virologic investigations were performed and showed results indicative for pox virus infectious. Electron microscopic inspection is being undertaken and an attempt to culture the virus will be made. Results of these investigations will be presented. Skin lesions, suspicious for pox virus infection, are rarely found at necropsy of stranded or by-caught harbor porpoises from European waters. It seems that the virus tends to spread out under immunosuppression condition in captivity.