Abstract

An adult male South American sea lion (Otaria flavescens) stranded alive on 12 August 2017 at Pantano do Sul, Florianópolis (27°78’31’’, 48°50’65’’), South Brazil. The animal was rescued by Associacão R3 Animal through the Santos Basin Beach Monitoring Project (Projeto de Monitoramento de Praias da Bacia de Santos—PMP-BS). This is one of the monitoring programs required by Brazil’s federal environmental agency, IBAMA, for the environmental licensing process of oil production and transport by Petrobras at the pre-salt province (25°05’S 42°35’W and 25°55’S 43°34’W), between 2100 m and 2300 m isobaths. The sea lion was in a cachectic condition, and clinical signs observed were nasal discharge, pneumonia, diarrhea and fever (rectal temperature 41,1°C). The sea lion died 7 days after stranding, and complete postmortem examination was performed. Tissues were collected from multiple organs and frozen at -20°C and fixed in 10% neutral buffered formalin for histological evaluation. Gross necropsy revealed a caseous mass in right prescapular lymph node, foamy fluid in oral cavity and in tracheal lumen and several pulmonary nodules; these were both subpleural and hard in consistency. Significant histopathological findings were observed in prescapular lymph nodes (multifocal necrotizing lymphadenopathy), lungs (severe multifocal necrotizing pneumonia associated with an interstitial fibrosis, edema, mineralization, emphysema, atelectasis and moderate parasitic infection), spleen (mild depletion of lymphoid follicles with moderate hemosiderosis), intestine (mild lymphoplasmacytic enteritis), heart (moderate cardiomyocyte degeneration with mild multifocal fibrosis), kidneys (moderate multifocal necrotizing nephritis with moderate multifocal interstitial lymphoplasmacytic nephritis), liver (moderate portal and periacinar fibrosis with mild biliary hyperplasia) and central nervous system (severe and diffuse gliosis and satellitosis). Proteus mirabilis was isolated from cardiac blood. PCR for alphaherpesvirus on frozen samples obtained from prescapular lymph node was positive. Sequencing is being performed to confirm alphaherpesvirus infection.

*Presenting author