I just had a wild thought about a movie (I think) from around the late 80s/early 90s, about a dog which had been genetically engineered (for war?) with killer instinct, greater intelligence and certain body modifications that was released from the lab by animal rights activists(?) and ended up adopted as a stray by a family with kids.
I remember the dog having retractible claws and climbing a tree at one point, and of course, the upshot of the premise that I remember was that the dog ended up stalking and killing anyone who hassled family members.
I’ve been trying to remember more about it, but I’m not even sure about the breed…I thought it was a St. Bernard but I can’t find any mention of anything similar googling “St. Bernard movies”.