Causes of mortality in a population of marine-foraging river otters (Lontra canadensis)

Abstract

Retrospective analysis of diagnostic findings from 30 marine-foraging river otter (Lontra canadensis) carcasses opportunistically acquired between 2003 and 2013 revealed trauma as the most common cause of mortality (47%). Within this focal population, causes of trauma included vehicular, gunshot, and one case of suspect intraspecific aggression. Other causes of death included idiopathic (20%), infectious (13%), metabolic (10%), nutritional (7%), and neoplasia (3%). One case of neoplasia, a pancreatic islet cell adenoma, was identified in a 12-yrold female. In six animals, diffuse renal interstitial fibrosis and multifocal glomerulosclerosis of unknown clinical significance were noted.