Police Dog (film)

Police Dog is a 1955 British crime film directed by Derek Twist and starring Charles Victor, Nora Gordon, Cecil Brock, John Le Mesurier, James Gilbert, and Christopher Lee.
Plot.
Constables Mason and Hill spot a burglar leaving the scene of the crime and both give chase, but Hill is badly shot by the burglar before Mason can catch up. Back at the police station Mason befriends Rex, a stray Alsatian dog recently brought in by another officer. Now living abroad, its owners agree to donate it to the police and it and Mason begin training together, causing tensions back home with Mason's girlfriend Pat Lewis, daughter of his landlady and her late policeman husband - Pat resents being unable to treat Rex as a pet and his drawing Mason's attention away from their relationship. Rex and Mason complete their training and go on patrol on the streets of Hampstead. 
In the meantime Hill has died of his injuries and his killer continues to lie low, taking on temporary work at a builder's until the CID arrive and he has to flee. Mason and Pat's relationship becomes more and more strained and he decides to move himself and Rex out. Soon afterwards he and Rex are deployed to a factory where Hill's still-armed killer is breaking into a safe. They pursue him, with Rex holding onto the killer long enough to make an arrest. Meaning to meet Mason for a final discussion about their relationship, Pat arrives at the crime scene and instead reconciles with both Mason and Rex.
Critical reception.
"TV Guide" noted an "average police drama, produced under the auspices of Douglas Fairbanks, Jr.'s, production company."
"Radio Times" called the film a "competent quota quickie...It's hardly a baffling mystery even Scooby-Doo would have sussed it! However, it's always nice to see class acts like John Le Mesurier and Christopher Lee, no matter how briefly."