A man pulled a gun on an individual who tried to prevent him from leaving a pet store after a child was bitten by a dog there Saturday afternoon, authorities said. Gainesville police arrived at the PetSmart on Dawsonville Highway at about 5 p.m. Saturday after a call that a child had been bitten by a dog in the store, police spokesman Cpl. Kevin Holbrook said Monday. According to the police report, witnesses tried to stop the two men with the dog from leaving the store.