Assessment and health status of macropod populations on Maria Island, June to July 2010

A limited epidemiological study of the health status of three major introduced macropods (Forester kangaroos (Macropus giganteus), Bennett's wallabies (Macropus rufogriseus) and Tasmanian pademelons (Thylogale billaderii)) on Maria Island was made in June-July 2010. The aim was to detect the presence or absence of disease, in particular disease related to over stocking, within the macropod populations. 7-9 animals were necropsied from each species, biased towards those animals that appeared lethargic I ill-thrifty. Gross exam (including kidney fat index), histopathology of gross lesions, parasitology (faecal egg count, total worm counts), haematology, biochemistry, toxoplasma serology and faecal salmonella culture were completed. Key findings were low kidney fat index in all macropods, indicating low nutritional status, moderate parasitic burdens in wallabies (3565±1937 eggs per gram of faeces, mean ± SD n=6) and pademelons (3278± 1085 eggs per gram faeces, mean ± SD n=6), anaemia in all macropods and hypoproteinaemia in wallabies. In addition, in all pademelons sampled there was peritonitis with intraperitoneal filarids (Brienlia thylogali). One wallaby had a diffuse subacute marked typhlitis with fibrinoid vasculitis and multifocal mild subacute necrotizing hepatitis. None of the animals sampled were shedding salmonella in faeces and none seroconverted to Toxoplasma gondii. This data, in conjunction with ecological data (including macropod population numbers, flora diversity I feed abundance), was used by Tasmanian Parks and Wildlife Service (P&WS) to make decisions for macropod population control.