Police said Troy Helms, 11, of Grove was attacked Saturday after falling during the Strut Your Mutt dog walk, sponsored by the Humane Society of Grove and Grand Lake, a private organization, the Tulsa World reported Wednesday.
The owner of the dog was cited by police.
"People don't realize how dangerous dogs can be," said Dave Helms, the boy's father.
"I saw the dog bite," Lori Follis, Humane Society vice president, told the World. "(The dog) clamped down on his face. He had his face and neck in his mouth. It was horrifying."
The dog was taken to an animal hospital, where authorities learned its rabies vaccination was not current, Grove City Manager Bruce Johnson said.