ABSTRACT. Soibelman D.C., Costa G.C.S., Sturzenecker M.R.T. & Fernandes J.I. [Gastroenteritis in dog associated with Cryptosporidium sp: endoscopic and histopathologic changes - Case report.] Gastroenterite associada a Cryptosporidium sp. em cão: alterações endoscópicas e histopatológicas - Relato de caso. Revista Brasileira de Medicina Veterinária, 37(supl.1):77-80, 2015. Programa de Pós-Graduação em Saúde Animal no Amazônas, Universidade Federal do Pará, Campus II, BR 316 Km 62, Castanhal, PA 68743-970, Brasil. E-mail: deboracostabile75@gmail.com A male canine, no breed, with three years old was examined complaining of intermittent vomiting and sporadic diarrhea. During the endoscopic examination the gastric mucosa was very swollen and hyperemic and inflammation in pylorus with bilious reflux. During the procedure, the duodenal mucosa was grossly swollen and hyperemic; suggesting enanthematous pangastritis and duodenitis. The histopathological evaluation revealed chronic superficial gastritis fundic discrete foveolar hyperplasia; pyloric mucosa with superficial epithelial bodies with Cryptosporidium sp; surface fragments of intestinal villi with rare forms compatible with Cryptosporidium sp.