title: A systematic health assessment of indian ocean bottlenose (Tursiops aduncus) and indo-pacific humpback (Sousa plumbea) dolphins incidentally caught in shark nets off the KwaZulu-Natal Coast, South Africa.
abstract: Coastal dolphins are regarded as indicators of changes in coastal marine ecosystem health that could impact humans utilizing the marine environment for food or recreation. Necropsy and histology examinations were performed on 35 Indian Ocean bottlenose dolphins (Tursiops aduncus) and five Indo-Pacific humpback dolphins (Sousa plumbea) incidentally caught in shark nets off the KwaZulu-Natal coast, South Africa, between 2010 and 2012. Parasitic lesions included pneumonia (85%), abdominal and thoracic serositis (75%), gastroenteritis (70%), hepatitis (62%), and endometritis (42%). Parasitic species identified were Halocercus sp. (lung), Crassicauda sp. (skeletal muscle) and Xenobalanus globicipitis (skin). Additional findings included bronchiolar epithelial mineralisation (83%), splenic filamentous tags (45%), non-suppurative meningoencephalitis (39%), and myocardial fibrosis (26%). No immunohistochemically positive reaction was present in lesions suggestive of dolphin morbillivirus, Toxoplasma gondii and Brucella spp. The first confirmed cases of lobomycosis and sarcocystosis in South African dolphins were documented. Most lesions were mild, and all animals were considered to be in good nutritional condition, based on blubber thickness and muscle mass. Apparent temporal changes in parasitic disease prevalence may indicate a change in the host/parasite interface. This study provided valuable baseline information on conditions affecting coastal dolphin populations in South Africa and, to our knowledge, constitutes the first reported systematic health assessment in incidentally caught dolphins in the Southern Hemisphere. Further research on temporal disease trends as well as disease pathophysiology and anthropogenic factors affecting these populations is needed.
authors.affiliation: Department of Research and Scientific Services, National Zoological Gardens of South Africa, Pretoria, South Africa.
authors.forename: Emily P
authors.initials: EP
authors.lastname: Lane
authors.affiliation: Epidemiology Section, Department of Production Animal Studies, Faculty of Veterinary Science, University of Pretoria, Pretoria, South Africa.
authors.forename: Morné
authors.initials: M
authors.lastname: de Wet
authors.affiliation: Epidemiology Section, Department of Production Animal Studies, Faculty of Veterinary Science, University of Pretoria, Pretoria, South Africa.
authors.forename: Peter
authors.initials: P
authors.lastname: Thompson
authors.affiliation: Institute for Terrestrial and Aquatic Wildlife Research, University of Veterinary Medicine, Hannover, Foundation, Germany.
authors.forename: Ursula
authors.initials: U
authors.lastname: Siebert
authors.affiliation: Department of Pathology, University of Veterinary Medicine, Hannover, Foundation, Germany.
authors.forename: Peter
authors.initials: P
authors.lastname: Wohlsein
authors.affiliation: South African Institute for Aquatic Biodiversity, c/o Port Elizabeth Museum/Bayworld, Port Elizabeth, South Africa.
authors.forename: Stephanie
authors.initials: S
authors.lastname: Plön
mesh_terms: D000818:Animals; D050681:Bottle-Nosed Dolphin / Q000469:parasitology* / Q000502:physiology*; D017753:Ecosystem; D006801:Humans; D019156:Indian Ocean; D060368:Lobomycosis / Q000473:pathology; D008297:Male; D012523:Sarcocystosis / Q000473:pathology; D013019:South Africa