Skin diseases in Guiana dolphins (Sotalia guianensis) from the Paranagua estuary, Brazil: A possible indicator of a compromised marine environment

Abstract

We report on the presence of lobomycosis-like disease (LLD) and nodular skin disease (NSD) in a community of Guiana dolphins (Sotalia guianensis) inhabiting the biologically and chemically contaminated Paranagua estuary (Brazil) and on their absence in the community living in the cleaner Cananeia estuary. Prevalence rates of LLD and NSD were 3.9% and 12.6%, respectively, in 103 photo-identified (PI) dolphins from the Paranagua estuary in the period 2006-2007. Adults and calves were affected. Lobomycosis-like lesions may be extensive and form large plaques. Skin nodules were sometimes ulcerated and associated with cutaneous traumas suggesting that traumatic injuries may play a role in the pathogenesis of this condition, In two adult dolphins, NSD evoked the beginning of LLD. In 1996-2007 none of he 200 PI Cananeia S, guianensis had LLD or NSD, a highly significant difference. Interestingly, these dolphins were reported to harbour relatively low concentrations of organochlorines. LLD and NSD are possibly indicators or environmental changes. (C) 2008 Elsevier Ltd. All rights reserved.