CHELSEA, Mich. (AP) — Authorities say a dog and a puppy were brutally attacked with a hatchet, and their injuries were so severe that both had to be euthanized.

The Humane Society of Huron Valley says that wounds to the dogs were inflicted with a hatchet while the animals were bound.

The Detroit News reports that both dogs — a 5-year-old shepherd mix and a 9-month-old Rottweiler mix — played together daily in their neighboring backyards about 50 miles west of Detroit and went missing March 9.

AnnArbor.com says they were found near death later that day, and veterinarians tried to save them but both had to be euthanized.

Officials are warning pet owners in the area that dogs running loose may be in extra danger, and are offering a $500 reward for information.