Abstract

The water vole (Arvicola amphibius) is Britain’s rarest native mammal and, in the wild, has an average life expectancy of <1 year, with few individuals surviving their second winter. During 2006 and 2007, over 300 water voles were housed and managed at Chester Zoo as part of breed and release/relocation program. This poster summarizes the findings of 51 postmortem examinations (approximately 50% of all reported deaths) that were performed during this period.

The most frequent postmortem diagnoses were dental disease, respiratory disease, and neoplasia. These accounted for >40% of the postmortems, with a mean age of almost two years. Chronic, degenerative/progressive diseases are of welfare concern as the animals have often undergone a period of disease and deterioration before they are diagnosed. Successful, curative treatment of these diseases can be difficult, if not impossible. Thus, to improve the welfare of captive populations of water voles, we need to consider if there are improvements in diet and/or husbandry that may prevent the onset of some of these diseases. If not, then euthanasia at the end of their “natural” lifespan should be considered as a management option for captive populations of water voles.