Lobomycosis-like disease in wild bottlenose dolphins Tursiops truncatus of Laguna, southern Brazil: monitoring of a progressive case.

Lobomycosis is a chronic dermal infection affecting humans and small cetaceans. In 1993, a study identified the presence of the etiologic agent of lobomycosis in a resident population of Tursiops truncatus (bottlenose dolphin) in Laguna, Brazil. Until now, no additional information relating to the persistence or prevalence of this pathogen in this population has been available. Numbering less than 60 animals, the residency of these dolphins in an impacted lagoon system has raised concerns about the health and viability of this small population. Using photo-identification data collected between September 2007 and September 2009, this study evaluated the occurrence of lobomycosis-like disease (LLD) throughout this population. Of 47 adult dolphins and 10 calves identified, 7 (12%) presented some form of epidermal lesion and 5 (9%) had evidence of LLD. The lesions were stable in all but 2 cases, in which a progressive development was recorded in a presumed adult female and her calf (referred to here as the LLD pair). During the first few months of observation, the lesion grew slowly and at a constant rate on the adult. However, in the fourteenth month, the growth rate increased rapidly and the first lesions appeared on the calf. Compared to the rest of the population, the LLD pair also presented a different spatial ranging pattern, suggesting a possible social or geographic factor. Current and previous records of LLD or lobomycosis indicate that the disease is endemic in this population. These findings highlight the importance of monitoring both the health of these cetaceans and the quality of their habitat.