NONNEOPLASTIC LESIONS IN BELUGA WHALES (DELPHINAPTERUS-LEUCAS) AND OTHER MARINE MAMMALS FROM THE ST-LAWRENCE ESTUARY

In a 3-year (1988-1990) pathological study, 24 carcasses of beluga wha les from the St Lawrence Estuary, Quebec, Canada, showed numerous seve re lesions, many of which had never been reported in cetaceans. The mo st common lesions were found in the digestive tract (21 animals) and c onsisted mainly of periodontitis and of erosions and ulcers in the oes ophagus and the first two gastric compartments. Pneumonia, usually of parasitic origin, was also a common finding (12 animals). The adrenal glands often contained nodules (five animals) or cysts (seven animals) , and mastitis was observed in five females. Overall, the incidence of degenerative, infectious, hyperplastic or necrotic lesions, in additi on to numerous neoplasms described in another paper, was considerably higher than that found in marine mammals elsewhere or in other species of marine mammal from the same waters.