Police are hunting a thug who set his rottweiler on a man outside a shop in Parr.
The animal bit the victim before the dog and its owner walked off in the direction of Chancery Lane.
The violent assault happened on Friday, January 8 at around 9.50pm.
Police say the 23-year-old victim was walking with a friend towards a local shop on Chancery Lane.
He was approached by an unknown man who had the dog with him.
Without warning he ordered the dog to bite the victim.
He suffered three puncture wounds on his calf, which required hospital treatment.
The offender is described as white, in his late 20s, early 30s of stocky build and around 5ft 8in tall.
Det Sgt Jackie Guinness said: “This was a nasty attack on a man, who was going about his day to day business and seemed to be completely unprovoked.
“We are particularly keen to speak with any dog walkers or residents in the Chancery Lane and Gaskell Park area, who might recognise him as a dog owner in the area to get in contact.”
Detectives would urge anyone with any information about this incident to contact St Helens CID on 0151 777 6887/6804 or Crimestoppers anonymously on 0800 555 111.