A woman attacked by a dog is in a stable condition following emergency surgery.
Chris Davis was forced to stab the dog several times
Kayleigh Thornton, 20, from Plymouth suffered severe arm and leg injuries and was taken to Derriford Hospital for surgery. A second woman was also hurt.
Neighbour Chris Davis, 23, was forced to kill the crossbreed animal by stabbing it several times.
The incident happened in Manifold Gardens in the Efford area of Plymouth on Thursday morning.
Ms Thornton is thought to have been looking after the dog at a house in the area.
It is believed she was attacked after trying to intervene when the animal bit a 31-year-old woman who had come to the front door.
Mr Davis described the dog as "huge and angry" and said it had "gone berserk".
He described how he stabbed the animal about 20 times before it started to stagger and released the woman's arm.
Although he was not bitten by the dog, Mr Davis suffered scratches on both arms and will be given a tetanus injection.
The dog's body was taken away by Plymouth City Council.
Sgt Alan Mobbs of Devon and Cornwall Police said the dog - a bull mastiff-type - was not classed as a dangerous breed.
Its owner has now been traced.