Pathology in skeletons of Peale's dolphin Lagenorhynchus australis from southern South America

Abstract

Peale's dolphin Lagenorhynchus australis is frequently seen off the coast of southern South America, where it feeds among coastal kelp beds and occasionally strands. We searched for macroscopic evidence of skeletal lesions in 78 specimens of Peale's dolphin from 2 museum collections, which contain almost all of the species' skeletons known in collections worldwide. Thirtytwo specimens (41%) had some type of osteological abnormalities. In 21 cases (66%), congenital deformations were the most predominant abnormality found. Acquired lesions included (1) induced trauma: abnormal curvature (n = 5 specimens) and fractures (n = 2); (2) infectious diseases: spondylo-osteomyelitis (n = 3); and (3) degenerative diseases: exostoses (n = 8) and spondylosis deformans (n = 4). It is noteworthy that all of these animals died incidentally in gillnet entanglement and were presumably healthy at the time of death. The effect that different osseous lesions may have on an animal's quality of life may depend on the area of the spine affected and the number of vertebrae involved.