The owner of a large white dog that attacked another dog walker in Markeaton Park has been urged to contact the police.
A woman was walking her two Jack Russells on the golf club in the park when the dog attacked at 10.10am on Wednesday 27 April.
The owner of the white dog tried to control his dog, but the woman was bitten on her hand after attempting to rescue her dog.
The owner of the white dog is described as white, balding and of medium build, in his late 30s or early 40s. He wore a black tracksuit and Nike trainers.
Police are appealing for the man to come forward.