Massive cystic tetrathyridiosis in a dog.

This report describes a case of massive cystic tetrathyridiosis in a four-year-old female dobermann. The larvae were distributed in both the peritoneal and pleural cavities, as well as in the lumen of the small intestine along with adult Mesocestoides species. These parasites were identified as tetrathyridia. Numerous cysts were dispersed on the peritoneal, pleural and mesenteric surfaces. The same cysts were seen both on subcapsular surfaces and within sections of the spleen, liver, kidneys and lungs. Histopathological examination also revealed characteristics of tetrathyridium of Mesocestoides species.