Suspected cases of Neorickettsia-like organisms in Brazilian dogs.

Preliminary findings of gross and histopathological lesions consistent with salmon poisoning disease in 10 dogs from southern Brazil are described. Lesions were restricted to the spleen, lymph nodes, and intestinal lymphoid tissues. Grossly, there was marked hyperplasia of mesenteric lymph nodes and Peyer's patches. Microscopic alterations were characterized by diffuse hyperplasia of intestinal lymphoid tissues and Peyer's patches. Intracytoplasmic organisms consistent with Neorickettsia helminthoeca were demonstrated by Giemsa stain in reticuloendothelial cells of the intestine, spleen, Peyer's patches, and lymph nodes. We have named this organism Neorickettsia helminthoeca-like because of its marked similarity with the agent described in the United States.