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Presence of Neospora caninum DNA was detected in the brain and spinal cord of an adult Merino sheep suspected of dying with acute non-suppurative meningoencephalitis and mild to moderate non-suppurative myelitis. The most severe neurological lesions were found in the midbrain at the rostral coliculi with moderate to severe multifocal vasculitis and gliosis. As this was the first known occurrence of cerebral disease in sheep in Australia caused by N. caninum, we surveyed sera from five sheep properties in New South Wales (NSW) to obtain information on the likely prevalence of N. caninum infection in NSW sheep flocks. Serology using a commercial indirect enzyme-linked immunosorbent assay (ELISA) revealed no N. caninum antibody-positive sheep (n=184). However an observed prevalence for N. caninum antibodies using a commercially available competitive ELISA was 2.2% (5/232). We conclude that although the diagnosis of fatal ovine cerebral neosporosis is of importance to our surveillance program for transmissible spongiform encephalopathy (TSE) exclusion, sheep in NSW are not commonly infected with N. caninum and this species likely plays only a minor role in the life cycle of this parasite in Australia.

Extensive translocation of wildlife throughout North America has led to concerns regarding taxonomic integrity for a number of species. Often, multiple subspecies or variants were translocated into a common habitat or region, creating the opportunity for hybridization to occur. This issue is of particular concern to managers of wild turkeys (Meleagris gallopavo), a species in which considerable mixing of subspecies has occurred. We aim to quantify the subspecific status and degree of hybridization of individuals within an introduced population of Merriam's turkeys (M. g. merriami) in the Davis Mountains of Texas, USA, and within nearby Rio Grande turkey populations (M. g. intermedia). We used data from the Merriam's source population in New Mexico, USA, as a baseline reference for the genetic characteristics of the Merriam's subspecies. Nineteen years following the introduction event, microsatellite data indicate that the genetic integrity of the introduced population of Merriam's turkeys in the Davis Mountains Preserve has been eroded by both immigration from and hybridization with nearby Rio Grande populations. Data from the mitochondrial control region allow for further characterization of hybrid individuals and indicate that most hybrids were the result of immigrant Rio Grande males mating with resident Merriam's females. Our results attribute to the potential importance of hybridization in wildlife species and suggest that hybridization can be a rapid process capable of drastically altering the evolutionary integrity of animals in a region.

Experimental infections of Sminthopsis crassicaudata, the fat-tailed dunnart, a carnivorous marsupial widely distributed throughout the arid and semi-arid zones of Australia, show that this species can act as an intermediate host for Neospora caninum. In contrast to existing models that develop relatively few N. caninum tissue cysts, dunnarts offer a new animal model in which active neosporosis is dominated by tissue cyst production. The results provide evidence for a sylvatic life cycle of N. caninum in Australia between marsupials and wild dogs. It establishes the foundation for an investigation of the impact and costs of neosporosis to wildlife.

In December 2008, a southern white rhinoceros (ãsimum simum) aborted a 7-mo gestation male fetus. On hematoxylin and eosin-stained sections of fetal tissues, foci of necrosis were noted in the hepatic parenchyma and were associated with low numbers of lymphocytes, plasma cells, and neutrophils. Protozoal zoites were identified within the hepatic lesions and within the cerebellum. Evaluations utilizing immunohistochemistry, polymerase chain reaction, and DNA sequencing identified the protozoan as Neospora caninum. A microsatellite analysis using MS10 marker showed a unique trinucletoide repeat pattern (ACT), (AGA)19 (TGA)8 distinct from all studied N. caninum to date. This is the first report of N. caninum-related abortion of a rhinoceros fetus of any species and the first report of polymerase chain reaction-confirmed N. caninum infection in any rhinoceros.