The dog and its handler were at Riversdale Kindergarten for an educational visit and when Tyler was waiting to pat the unrestrained dog, it bit him on the face.
He was left with two minor puncture wounds on his lip and a cut to his nose. A doctor assessed his wounds but Tyler did not require treatment.
District operations manager Inspector Mike O'Leary said the incident was unusual and police were investigating.
The dog was having its health, physical condition and behavioural status reassessed by a senior dog handler.
"The handler is devastated that his dog could have done this to a small child and is very upset by the incident," he said.
Tyler's father, Matthew Hatton, said that his son was upset by the incident and did not want to be around dogs.
However, Mr Hatton did not want the dog to be put down as he knew how much went in to training a police dog.
The Napier Kindergarten Association will also investigate the incident and review if dog visits will continue.
- Hawkes Bay Today.