The body of 76-year-old Ernest Rumpel was recovered Saturday evening from Cummins Lake.
Police said they believe Rumpel's dog, a German Shepherd, rocked his canoe — capsizing it and sending Rumpel into the water.
He was not wearing a life jacket.
"There were witnesses on the shore, but no one was in a position to get to him quickly enough," said Thunder Bay OPP Staff Sergeant Jim Graham.
The victim was recovered by East Gorham and Lappe Fire Service volunteers using cold water immersion suits.