Neosporosis in an aborted southern white rhinoceros (Ceratotherium simum simum) fetus.

In December 2008, a southern white rhinoceros (Ceratotherium simum simum) aborted a 7-mogestation 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)(6) (AGA)(19) (TGA)(8) distinct from all studied N. cantonal 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.