Hosts: Dog, cat, dingo.
Location: Unknown. Oocysts found in feces.
Geographic Distribution: Europe (England, Holland), North America (Nebraska, Quebec), Australia.
Prevalence: This form is uncommon. It was found by Brown and Stammers (1922) and Wenyon (1923) in England, Nieschulz (1924) in Holland, Skidmore and McGrath (1933) in Nebraska and Bearup (1954) in a dingo in Australia. Choquette and Gelinas (1950) reported it in 10% of 155 dogs in Quebec.
Morphology: The oocysts are ovoid or ellipsoidal, 17 to 45 by 11 to 28 u, pink, red or colorless. The oocyst wall is fairly thick, rough, and composed of 2 layers. A micropyle is present. The sporocysts measure 9.5 by 2.5 u. The sporulation time is 1 to 4 days.
Remarks: It is far from certain that this is a valid species. Wenyon (1926) remarked that in many respects E. canis resembles a mixture of E. stiedae and E. perforans of the rabbit, and Goodrich (1944) considered it to be a rabbit form which the dogs had eaten.