Miscellaneous skin lesions of unknown aetiology in cetaceans from South America.

L. FLACH, M-F VAN BRESSEM, J.C. REYES, M. ECHEGARAY, S. SICILIANO, MARCOS SANTOS, F VIDDI, E CRESPO, J. KLAICH, I. MORENO, M. TAVARES, P.H. OTT, EMIN-LIMA, N.R., FERNANDO FELIX & K. VAN WAEREBEEK

Santiago de Chile, Chile

Workshop; WORKSHOP ON CETACEAN SKIN DISEASES. INTERNATIONAL WHALING COMMISSIONN; 2008

We report on miscellaneous skin diseases or syndromes of unknown aetiology including whitish, velvety lesions (WVL, often associated with unrelated skin injuries, scars and tooth rakes), large, rounded lesions (LRL, large to very large lesions with an orange or dark outline and a light inner colour) and vesicular skin disease (VSD, small to medium vesicles) in Megaptera novaeangliae, Cephalorhynchus commersonii, C. eutropia, Pseudorca crassidens, Sotalia guianensis and Tursiops truncatus from marine waters of Argentina, Brazil, Chile, Ecuador, Peru and the Antarctic. No biopsy samples have been available yet for histopathology. WVL are now commonly recorded opportunistically through photo-identification studies in several coastal species and populations from South America. Mortality rates, if any, associated with these skin diseases is unknown. Though sometimes extensive and ulcerated WVL do not seem life-threatening and, at least in some individuals, may eventually heal. A calf C. eutropia with LRL died some weeks after being first sighted. While unknown bacteria or fungi superinfecting miscellaneous skin traumata and poxvirus tattoos are thought to cause WVL and LRL, vesiviruses are suspected as the aetiological agents of VSD. Importantly, all lesions were primarily seen in coastal cetaceans living in biologically or chemically contaminated waters. These various skin conditions may be indicative of a deteriorating coastal water environment and should be systematically monitored. Collection of biopsies or fresh samples for histopathology and microbiological analysis is urgently needed.Megaptera novaeangliae, Cephalorhynchus commersonii, C. eutropia, Pseudorca crassidens, Sotalia guianensis and Tursiops truncatus from marine waters of Argentina, Brazil, Chile, Ecuador, Peru and the Antarctic. No biopsy samples have been available yet for histopathology. WVL are now commonly recorded opportunistically through photo-identification studies in several coastal species and populations from South America. Mortality rates, if any, associated with these skin diseases is unknown. Though sometimes extensive and ulcerated WVL do not seem life-threatening and, at least in some individuals, may eventually heal. A calf C. eutropia with LRL died some weeks after being first sighted. While unknown bacteria or fungi superinfecting miscellaneous skin traumata and poxvirus tattoos are thought to cause WVL and LRL, vesiviruses are suspected as the aetiological agents of VSD. Importantly, all lesions were primarily seen in coastal cetaceans living in biologically or chemically contaminated waters. These various skin conditions may be indicative of a deteriorating coastal water environment and should be systematically monitored. Collection of biopsies or fresh samples for histopathology and microbiological analysis is urgently needed.