Rent Beethoven (1992)

Barely escaping from nefarious dognappers, an adorable puppy named Beethoven adopts the unsuspecting Newton family - and promptly grows up into 185 pounds of romping, drooling, disaster-prone dog. Unfortunately, even after proving his canine credential to mom and the kids, the heroic hound gets nowhere with uptight dad, George (Charles Grodin). When a nasty veterinarian (Dean Jones) makes Beethoven the target of an unspeakable animal experiment, George becomes the only hope for saving the Newtons' furriest family member.