The six dogs that fatally mauled a 76-year-old woman showed no signs of having been used in fights, and felony charges against their owner are unlikely, authorities said.

Milam County Sheriff Charlie West said Monday that he and District Attorney Kerry Spears were unable to conclude that owner Jose Hernandez committed a felony. But West said a misdemeanor citation was possible against Hernandez, who kept the pit bull-Rottweiler mixed-breed dogs in a pen.

The six dogs attacked Lillian Loraine Stiles on Saturday as she worked in her front yard. She died at the scene; a passer-by who tried to help was bitten. Her husband fatally shot one dog, and the other five were euthanized Monday.

Authorities said Hernandez was cooperating in the investigation and had told officials that his young grandchildren had played with the dogs without incident.

"There are no laws that apply," West told the Austin American-Statesman. "We are still looking, but it is going to be hard to make anybody responsible for it."

"To him, the dogs weren't vicious," West said. "They were just pets."

A veterinarian who examined the dogs said there was no indication of injuries such as cuts or broken bones that would have indicated they had been used for fighting.

Neighbors said they had occasionally seen some of the animals but had never noticed them roaming as a pack.

The euthanized animals had been sent to the Texas Department of State Health Services for rabies and other testing, West said.