We report six cases of rabies (three confirmed, three suspected) in gr
ay wolves (Canis lupus) representing 21% of the total wolf mortality i
n a 5 yr study (1987 to 1992) of radiocollared wolves in Algonquin Pro
vincial Park, Ontario, Canada. Reports of rabies in wolves of the Grea
t Lakes region of North America are rare, even though wolf populations
have been studied extensively for almost 40 years. No cases have been
documented in wild wolves on the U.S. side of the Great Lakes, wherea
s, in Ontario, 15 cases have been documented since 1960.