Two pit bull terriers broke into a house through a pet door Tuesday and attacked a woman in her bed, mauling her badly, a Pierce County sheriff's spokesman said.

The woman was able to grab a gun and try to shoot the dogs, then break away from the attack and lock herself in her car, where she called 911, sheriff's spokesman Ed Troyer said.

The woman, who was not immediately identified, was taken to a hospital in Tacoma, where she was listed in serious condition.

Officers planned to talk to the dogs' owner.

The pit bulls also killed a neighbor's Jack Russell terrier, which entered the house during the attack, Troyer said.

"The thought is that the Jack Russell heard noise in the neighbor's house, came in and was attacked by the dogs," Troyer said.

Firefighters responded first, locking the dogs in the house, treating the woman and calling for an ambulance.

Officers "had to pepper spray and fight the dogs until they were detained. We almost had to shoot them on site," Troyer said.

The dogs were taken to a Humane Society and will probably be destroyed, he said.

It was not immediately known why the dogs entered the house, whether the woman had dogs of her own or what set off the attack.