A man takes his Rottweiler to the vet.
"My dog is cross-eyed, is there anything you can do for him?"
"Well," said the vet, "let's have a look at him" So he picks the dog up and examines his eyes, then he checks his teeth.
Finally, he says, "I'm going to have to put him down."
"What? Because he's cross-eyed?"
"No, because he's really heavy".