Sporulated Coccidian Oocysts Resembling Goussia Labbe, 1896 in the Viscera of Nile Crocodiles

摘要

Three dead adult Nile crocodiles (Crocodylus niloctius Laurenti, ) from a crocodile farm in Zimbabwe were submitted for evaluation. No gross lesions were seen at necropsy. Available for histology were pieces of liver, spleen and lung fixed in neutral-buffered 10% formalin. Tissues were processed routinely. Histologically the red pulp of the spleen was infiltrated by leucocytes, primarily lymphocytes, but the white pulp was still easily recognizable. There were many sporulated oocysts of a coccidian in the red pulp area and impinging on and within the periphery of the lymphoid sheaths. A mild hemosiderosis was present in the red pulp. Numerous oocysts were found within the interstitum of the lung. It was difficult to determine the exact location of the oocysts. It was determined that they were within macrophages or endothelial cells. Some oocysts were extracellular. Diffuse hydropic changes were present in hepatocytes. Oocysts were numerous in sinusoids and often were found in cells with flattened nuclei. These parasites were probably in Kupfer cells, but may have been in circulating macrophages. In general there was no inflammatory response to the parasites in any organ.