ABSTRACT
Species of the genus Sarcocystis are considered as important parasites of domestic animals. Dogs are considered as definitive host for a variety species of Sarcocystis, when they fed on intermediated host tissues cysts shed sporocysts in their feces. Grinded bovine cardiac muscles, positive for Sarcocystis cruzi was given to two puppies free of coccidia. Both animals shed sporocysts in their feces at 12 days after infection (DAI). These sporocysts measured 17.44 +/- 0.82 11.60 +/- 0.66 mum with shape index of 1.50 +/- 0.05. At 23 DAI, these animals were posted and samples of the small intestine, such as: duodenum, jejune, ileum and mesenteric lymph nodes were collected. In the analysis of small intestine, sporocysts were observed under de mucosa and they were characterized by sporulated sporocysts with sporozoites. Lesions were consisted of discrete edema and plasmocytic cells infiltrations which they were associated to a minimal inflammatory reaction in the presence of parasitic stages. On the other hand, sporocysts were observed at the cortical region near of lymphatic vessels adjacent to mesenteric lymph nodes capsule. It indicated the involvement of the lymphatic vessels in the sporocysts dispersion in the dog mesenteric lymph nodes.