A 10-year-old girl suffered serious facial injuries when she was badly mauled by a Staffordshire bull terrier in North Yorkshire.
The injured girl is the child of a service family
Emergency crews were called to an area close to Alanbrooke Barracks at Thirsk on Thursday evening.
The girl was taken to James Cook Hospital in Middlesbrough where she has undergone surgery to her cheek.
The dog's owner, a woman aged 21, was arrested on suspicion of having a dog dangerously out of control in public.
The animal was put down immediately.
North Yorkshire Police said it did not think the dog's owners were related to the girl's family.
Sgt Ben Frank said the girl's parents were "understandably extremely upset".
He said: "Nobody wants or expects this type of thing to happen.
"The owners of the dog have done the responsible thing. I'm sure that the family are still very distressed."
He added: "Owners of dogs have a clear responsibility to keep their dogs under control."
Sgt Frank said the girl had one cut to her face which was about 6cm long and 1cm deep.
A Ministry of Defence spokeswoman confirmed the girl was the child of a service family.
She said: "We are cooperating fully with the police.
"Obviously, people on the base keep pets as they do in civilian life."