Dog eye problem solved?

A man took his Rottweiler to the vet and said to the vet: "My dog's cross-eyed, is there anything you can do for it?"

"Well" said the vet "lets have a look at him"

So he picks the dog up and has a good look at it's eyes.

"Well" says the vet "I'm going to have to put him down"

"Just because he's cross-eyed?" says the man.

"No, because he's heavy" says the vet.