A preliminary overview of skin and skeletal diseases and traumata in small cetaceans from South American waters. SC/59/DW4, International Whaling Commission/SC, Anchorage, Alaska, May 2007
Van Bressem, M.-F.; Van Waerebeek, K.; Reyes, J.; Félix, F.; Echegaray, M.; Siciliano, S.; Di Beneditto, A.P.; Flach, L.; Viddi, F.; Avila, I.C.; Bolaños, J.; Castineira, E.; Montes, D.; Crespo, E.; Flores, P.A.C.; Haase, B.; Mendonça de Souza, S.M.F.; Laeta, M.; Fragoso, A.B. (2007). A preliminary overview of skin and skeletal diseases and traumata in small cetaceans from South American waters. SC/59/DW4, International Whaling Commission/SC, Anchorage, Alaska, May 2007. International Whaling Commission: Anchorage. 14 + figures + tables pp. |  |
| Authors | | Top | - Van Bressem, M.-F.
- Van Waerebeek, K., more
- Reyes, J.
- Félix, F.
- Echegaray, M.
- Siciliano, S.
- Di Beneditto, A.P.
| - Flach, L., more
- Viddi, F.
- Avila, I.C.
- Bolaños, J.
- Castineira, E.
- Montes, D.
| - Crespo, E.
- Flores, P.A.C.
- Haase, B.
- Mendonça de Souza, S.M.F.
- Laeta, M.
- Fragoso, A.B.
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| Abstract | Miscellaneous lesions of the skin and skeletal system, and external traumata were observed in 558 of 7,400 specimens of 12 odontocete species from the waters of Colombia, Ecuador, Peru, Chile, Argentina, Uruguay, Brazil and Venezuela examined in 1984-2007. Tattoo skin disease (TSD), lobomycosis-like and cutaneous diseases of unknown aetiology seem to be emerging in several populations and, in some cases, may be associated with chemical and organic water pollution. TSD was observed in eight species from the SE Pacific and SW Atlantic. Lobomycosis-like disease was found only in coastal Tursiops truncates but in four countries (Colombia, Ecuador, Peru and Brazil). All affected specimens were encountered in the vicinity of major ports, cities or shrimp farms. Whitish velvety cutaneous marks associated with scars occurred in coastal T. truncates (Peru), Sotalia guianensis (Brazil) and a Pseudorca crassidens (Ecuador). Large, rounded lesions were seen in a calf Cephalorhynchus eutropia (Chile) and a Cephalorynchus commersonii (Argentina). Cutaneous wounds and scars as well as body traumata related to net entanglements and boat collisions were observed in 62 dolphins and porpoises from both oceans. Traumata resulted in deformations as well as in the partial or complete amputation of the dorsal fin, flippers and flukes in 14 cases. Fractures of the skull, ribs and vertebrae thought to be caused by violent, fisheries-related interactions or boat collisions were seen in single individuals of Delphinus capensis (Peru), Lagenorhynchus obscurus (Peru), Ziphius cavirostris (Uruguay) and S. guianensis (Venezuela). Prevalence of osteopathology in dolphins and porpoises from Peru and Brazil ranged widely, from 5.4% to 69.1%. In four small cetacean species from Peru cranial lytic lesions were the most frequently observed disease (5.4%-40.5%), followed by hyperostosis and ankylosing spondylitis in offshore (31%) and inshore (15.4%) T. truncates. Fractures and other bone traumata were seen in 47.2% of the axial skeletons of S. guianensis collected along the northern coast of Rio de Janeiro State in 1987-1998. A high prevalence (48.4%, N=31) of, apparently congenital, malformations of the cervical vertebrae observed in a 2001-2006 sample may be linked to a hypothetical genetic bottleneck in this population. Malformations with deficient ossification would increase susceptibility to fractures of vertebrae. This study demonstrates the need for focussed research on the effects of human activities on the spread of infectious and other diseases in small cetaceans, particularly in near-shore populations that inhabit a highly degraded coastal environment. |
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