Retrospective analysis of causes of death in mountain pygmy-possums (Burramys parvus) at Healesville Sanctuary, Victoria, Australia.

Abstract

BACKGROUND: Identification and characterisation of deaths is important for the veterinary management of both wild and captive animals. It is especially important as a tool for monitoring health and disease within populations of endangered species for which little information on morbidity and mortality is known. Investigations into the causes of death and other important necropsy findings were made in a captive population of the critically endangered mountain pygmy-possum (Burramys parvus). METHODS: Necropsy records from January 2000-December 2013 were reviewed for all possums that had lived and died at Healesville Sanctuary (n = 48). RESULTS: The average age of death of possums in this population was 4.7 years. The most common histological change in mountain pygmy-possums was varying degrees of chronic progressive kidney disease (n = 17). Of these cases, eight animals (47%) had histological changes suggesting the kidney disease was the likely cause of death. Other causes of death included neoplasia (n = 5), necrotising pancreatitis (n = 4), pneumonia (n = 2), reproductive disease (n = 2) and trauma (n = 2). No cause of death was able to be identified in 33.3% (n = 16) of cases. Hepatic lipidosis (n = 5), pneumonia (n = 2) and degenerative joint disease (n = 2) were the most common comorbidities found. CONCLUSION: Progressive renal disease, often with secondary metastatic mineralisation, appears to be a significant cause of mortality in captive mountain pygmy-possums and further investigation into its pathophysiology, antemortem diagnosis and treatment is warranted.