The brush-tailed bettong (Bettongia penicillata), or woylie, is a medium-sized macropod marsupial that has undergone a rapid and substantial decline throughout its home range in the Upper Warren region of Western Australia over a period of approximately 5 years. As part of an investigation into possible causes of the decline a morphologically distinct Trypanosoma sp. was discovered by light microscopy in the declining population but was absent in a stable population within the Karakamia Wildlife Sanctuary. Further investigations employing molecular methods targeting variations in the 18s rRNA gene determined that the trypanosome was novel and was also present within the Karakamia population albeit at a much lower overall prevalence and individual parasitaemia levels. Phylogenetic analysis suggests the novel Trypanosoma sp. to be closely related to other trypanosomes isolated from native Australian wildlife species. Although it appears unlikely that the parasite is solely responsible for the decline in woylie population size, it may (singularly or in conjunction with other infectious agents) predispose woylies to increased mortality.

Haematology of Australian Mammals is a valuable guide to collecting and analysing the blood of Australian mammals for haematological studies and diagnosis and monitoring of disease. It outlines general principles for selecting sites for blood collection and for handling and analysing samples to achieve quality results. Chapters then describe the morphology and function of haematological cells, with reference to the known characteristics of Australian mammals in health and the changes that may be encountered in response to common diseases. Haemoparasites that have been encountered in Australian mammals are discussed next, along with comments on their pathogenicity. Lastly, haematological values from previously published studies are compiled into species-specific tables, providing a convenient reference to compare to the results of clinical cases. Written descriptions and colour photomicrographs of haematological cells from more than 100 species aid the identification of cells and the detection of abnormalities. Information is provided throughout for representative species from all the major groups of native Australian mammals including monotremes, polyprotodont marsupials, diprotodont marsupials, rats and mice, bats and marine mammals.

A syndrome affecting cultured chinook salmon, Oncorhynchus tshawytscha (Walbaum), characterized by distended abdomens, gastric dilation, air sacculitis (GDAS), increased feed conversion rates and increased mortality has been recognized in New Zealand. Affected fish were most obvious in sea cages but were also present in fresh water. Mortality rates associated with this condition were highest in late summer and approached 6% per month. A dilated and flaccid stomach, without visible rugal folds containing copious oil, watery fluid or undigested feed was typical. Gastric mucosal ulceration or inflammation were not present. The air sacculitis consisted of a thickened, dilated bladder with a mixed mucosal inflammatory infiltrate and a luminal exudate associated with large numbers of morphologically diverse bacteria. Gastric dilation or air sacculitis occurred alone or together in the same fish. In a group of 20 subclinically affected fish with or without gastric dilation, there were no significant differences in weight, length, serum osmolality, sodium, total protein or packed cell volume. Twenty‐three severely affected fish had significantly (P < 0.05) higher serum osmolality but similar sodium and total protein to that of clinically normal fish.

Characteristic changes in cytograms produced by the Advia 120 allowed recognition of artifactual changes in stored equine blood samples. These changes were less pronounced in samples stored at 24 degrees C than at 4 degrees C.

This study is the first confirmation of Rickettsia felis in Australia. The organism was identified from 4 species of fleas obtained from dogs and cats in Western Australia, by using polymerase chain reaction amplification and DNA sequencing of the citrate synthase and outer membrane protein A genes.