A state conservation officer said that such an attack is rare, but that it is becoming more common because the deer population is not as plentiful in rural areas of northeastern Minnesota, leading wolves to prowl for food in more urban surroundings.

Leo, an 11-year-old golden retriever-corgi mix, was not on a leash and was about 15 to 20 yards from its owner on a short trail near Brighton Beach when the wolf pounced about noon, said Keith Olson, a longtime conservation officer with the Minnesota Department of Natural Resources (DNR).

The dog's owner, Terry Irvin, of Duluth, said he didn't see the attack.

Olson went to the scene and said "the violence" of the kill site, the bite marks and the tracks convinced him that a lone wolf was responsible.

"That poor dog, Leo, was in the wrong place at the wrong time," said Olson, who described the trail as a favorite of dog owners who live near Lake Superior. "And lone wolves are a little more desperate."

Irvin said he and Leo, whom he and his wife adopted from a shelter nine years ago, went to the park two to three times a week "and we've never had a problem."

He said Tuesday's walk was like most others. "I got a little ahead of him, and I was waiting for him. And then I waited and waited, maybe five-six minutes, and called and whistled."

After checking areas off the quarter-mile trail, Irvin returned to where he had last seen Leo.

"I walked into the woods, and I saw him," he said. "It was a traumatic sight. I will never forget it. … It was heartbreaking."

Instances of wolves attacking pets in the city are "rare but getting more common," Olson said. "Duluth is a unique community. A lot of critters roam through Duluth."

Dogs are required by law to be on a leash in the area where Leo was attacked, said Carrie Lane, a shelter lead worker for the Police Department's animal services division.

"I understand the [desire] to have your dog off your leash and have it get exercise," Lane said. "But it appears that the number of wolves is growing, so it's probably not worth the trade-off."

Irvin said he never had Leo on a leash whenever they walked that trail. Leo's death "is entirely my fault," he said.

North Shore Veterinary Hospital, located near the beach, notified its clients of what had happened in a Facebook posting, explaining, "We want to share this information because many of us walk our pets in this area."

Holly Rosendahl, the hospital's staff manager, said the attack on Leo is the first time the facility has lost a client to a wolf, and she recalled an earlier attack that one of its dogs survived. Rosendahl said it's more common for deer and occasionally coyotes to harm dogs.

While it's best to keep dogs on a leash during walks, she added, that's no guarantee against a wolf pouncing.

"Wolves are pretty brave" in populated areas, she said. "They are not as fearful as we think they are. Desperate times call for desperate measures when they are hungry."

Paul Walsh • 612-673-4482

This wolf was photographed last September near Brighton Beach in Duluth. A dog on a trail near the same beach was attacked by a wolf and killed on Tuesday. (Jenni Pinkley/The Minnesota Star Tribune)