Police say the victim, 26, was severely mauled by the two dogs early Saturday at the suspect's home in Sundre in west-central Alberta. She suffered life-threatening wounds to her arms and face.
First responders initially thought she was dead.
"She was unresponsive and there very little signs of life," Insp. Frank Smart said Tuesday. "I know one of the RCMP officers had to actually drive the ambulance to the hospital for EMS individuals so they could both work on the female victim in the back of the ambulance," he said.
"The injuries were very severe and if you've ever seen wounds created by dogs when they can bite ... you're looking at wounds where flesh is actually taken off," Smart added.
"I believe the victim in this instance may have lost her entire ear."
Police have laid aggravated assault charges against Rita Phillip, 57, who lived in the home. Phillip disappeared shortly after the attacks.
"The RCMP had reasonable grounds to believe that she was responsible for the attack on our victim," said Smart.
"Her actions led to the dogs attacking the victim."
He said there has been no sign of Phillip and police don't know if she is still in the Sundre area.
Investigators interviewed the victim prior to laying the charges. She is listed in stable condition in a Calgary hospital.
Smart said police do not know what led to the attack. He said the two women were not related and were believed to be friends.
Police and EMS personnel encountered a chaotic scene when they arrived at the mobile home, said Smart. Witnesses had warned them that a young woman was inside and had been attacked by dogs.
Responders found her lying unconscious behind a closed bedroom door. The two dogs were in another room and were throwing themselves at the door trying to get out.
One of the animals was successfully sedated with the help of a veterinarian, but the other remained awake and charged officers when the door was opened and had to be shot.
"It charged some other RCMP members and had to be taken down."
The surviving dog was captured and may be destroyed pending the outcome of the police investigation.