A four-year-old girl has serious facial injuries from a dog attack in Masterton.
Police say the child was patting a bull mastiff on Saturday morning under the supervision of an adult when the dog became aggressive.
It then pinned the girl to the ground, biting her face.
She sustained serious facial injuries, which will require reconstructive surgery.
The dog, which police say had been a family pet for 10 years without problem, will be destroyed.
Acting Sergeant Tony Matheson says it is unclear why the dog attacked.
He says its owner was present at the address at the time and the dog was surrendered immediately.
Mr Matheson says if found guilty under the Dog Control Act, the owner could face a maximum penalty of three years in prison, or a $20,000 fine.