FAIRFIELD (CBS SF) — A 29-year-old Fairfield woman was severely mauled in her backyard by her own dog early Thursday before police shot it dead, authorities said.

Fairfield police said the attack took place in the woman’s backyard in the 1600 block of Kentucky St. A next-door neighbor called 911 to report they had heard the woman screaming and looked over the fence and saw a large dog attacking her.

Arriving officers could see the woman lying face down and bleeding profusely from both arms with a large dog standing over her.

The woman’s house has an unusually large yard, almost a full acre in size, and the attack was occurring in the farthest reach of the yard away from the home and street.

Authorities said the dog quickly alerted to the officer’s presence and charged the fence where the officers stood. One officer on scene fired his handgun at the charging dog out of fear of his safety, his fellow officers and the woman that had already been badly injured.

The dog stopped his attack and soon succumbed to his injuries.

Emergency aid was immediately provided to the woman, and the severity of her injuries were determined to be life-threatening. The woman was taken by ambulance to a local trauma center and later flown by helicopter to a surgical center in the Bay Area. She is listed in serious condition.

Investigators said the attack took place when she opened a backyard kennel — which housed several dogs — to provide the dog with water.

Neighbors told police there were about 20 dogs in the home’s backyard. Fairfield Police Lt. Greg Hurlbut said the dogs were described as a special breed of hunting dog.

It was not immediately known what breed of dog was involved in the attack or were being kenneled at the site. Solano’s County’s Humane Animal Services was the lead agency in the investigation according to the sheriff’s office. The agency did not immediate respond to questions about the case.