A man takes his dog to the vet. “My dog is crossed eyed, is there anything you can do for him? 

“Well,” says the vet, “let’s take a look at him.” 

So he picks the dog up and examines his eyes, then checks his teeth. Finally, he says, “I’m going to have to put him down.” 

“What? Because he is cross-eyed?”

“No, because he’s really heavy.”