Ten domestic dogs became infected with Sarcocystis when fed simple portions of heart, esophagus and diaphragm from a two-year-old female wapiti (Cervus canadensis). The prepatent period was 14 days in all exposed dogs; the patent period ranged from 8 to 20 days. Neither the 10 control dogs, nor two dogs fed sporocysts collected from the infected dogs passed sporocysts within the study period. Sporocysts averaged 16.5 by 11.1 micron in size.