A woman was bitten by a Belgian Shepherd while she was walking her dog in a park in Cheltenham.
Police are appealing for information after the incident which happened at around 7.30am last Tuesday (18 October) in Pittville Park.
The victim told police another man's dog was initially playing with her dog before it then became aggressive, chased her dog and attacked it.
The man's dog, a Belgian Shepherd, then bit her on the back of her leg causing a large puncture wound and two small puncture wounds.
The woman was left temporarily unable to bend her left knee.
The victim said the dog's owner asked her if she was okay, to which she replied "no, your dog just bit me."
He was apologetic but continued to walk his dog and did not provide any details.
The man was described as being white, aged in his 30s and wearing a black coat with a distinctive yellow strip down the side.
The owner of the dog or anyone with information is being urged to contact Gloucestershire Police.