1. Northern Blood Research Centre, Kolling Institute of Medical Research; University of Sydney; St Leonards NSW 2065 Australia
2. Faculty of Veterinary Science; University of Sydney; B10 Camperdown NSW 2006 Australia
3. North Shore Veterinary Specialist Centre; Crows Nest NSW 2065 Australia
4. Department of Haematology and Transfusion Medicine; Royal North Shore Hospital; St Leonards NSW 2065 Australia