A man was reportedly screaming inside a home in the 1000-block of Broder Street and two large dogs were loose outside and displaying aggressive behaviour, according to a press release.
Officers said they initially found two dogs able to move freely through the fence between the alley behind the house and the backyard.
When an officer exited his vehicle, both animals ran towards him in the alley and he drew his gun, taking several steps back and yelling, police said.
As the dogs closed in, the officer said he fired his gun in the direction of the larger dog and then both canines immediately retreated into the house.
The press release said the man emerged from the house and was informed by police that one of the dogs had been shot and needed medical attention.
Officers said the man continued to argue and was arrested for breach of the peace.
Police and animal control officers found the injured dog and two others inside the house. The injured one was taken for veterinary care.
Regina Humane Society informed police that the dogs had a documented history of aggressive behaviour and had been released from quarantine the day before, according to a press release.
RPS said reports have been submitted to its use of force review board.