Postcranial axial skeletal pathology in Commerson?s dolphins (Cephalorhynchus c. commersonii) from Tierra del Fuego, Argentina

ANALIA A. SAN MARTIN; NATALIA A. DELLABIANCA; EDUARDO J. GIMENO; MARIE-FRANÇOISE VAN BRESSEM

DISEASES OF AQUATIC ORGANISMS

INTER-RESEARCH

Lugar: Oldendorf/Luhe; Año: 2019

0177-5103

Commerson?s dolphins Cephalorhynchus c. commersonii are the small cetacean mostfrequently found stranded along the coast of Tierra del Fuego, Argentina, but little is known abouttheir pathologies. We examined the postcranial axial skeleton of 425 Commerson?s dolphins collectedin the period 1974−2011 for the presence of pathologies. Miscellaneous lesions weredetected in 107 (25.2%) of the specimens. Among them, idiopathic hyperostosis was the most frequentpathology (73.8%), followed by spondyloarthropathy (40.2%). Traumata (25.2%), spondylitis(10.3%) and osteoarthritis (11.2%) occurred less frequently. The type of lesion was statisticallyassociated with the region of the vertebral column. Idiopathic hyperostosis occurred significantlymore frequently in the lumbar vertebrae than in other parts of the vertebral column, while spondyloarthropathywas more frequent in the thoracic and caudal vertebrae. Both conditions werepredominantly seen in mature dolphins. Osteoarthritis affected the transverse processes of thethoracic vertebrae of 6 males, 3 females and 3 individuals of undetermined sex, all mature. Healedand unhealed fractures were observed in the ribs of 27 specimens and in the transverse processesof 3 others. Spondylitis of various degrees of severity affected the cervical, thoracic, lumbar andcaudal regions of 11 individuals. Together these data indicate that bone lesions and traumata commonlyoccur in Commerson?s dolphins, likely causing pain and morbidity in severe cases