Phil Leslie, 41, said soon after the Ontario Provincial Police issued a warning about "an animal of unknown nature" Tuesday afternoon, he found the 14 calves mutilated in Caledon, northwest of Toronto.
"There were calves' bodies all over the place," Leslie told the Toronto Star. "There were chew marks through their stomachs, where their intestines were hanging out. I'd never seen anything like it."
The first calls to police began Monday night when residents called about a "large, black animal" roaming through the rural community.
Canine expert Mike Martin told the Star he examined the animal and believes it was part wolf and part German shepherd or husky.
"These animals are really hard to work with and really hard to train because their brain doesn't work the same as a dog," he said.
Martin said the animal had a collar on, meaning someone had owned it and kept it captive.
"He finally broke his way out and followed his nose for food until he found the cows," he said. "But he didn't know how to eat them, so he basically got off on the kill."