"Shoulda Said" joke

This guy walks into a bar with his golden retriever. "Hey, can I get a drink on the house if my dog talks for you?"
"Dogs can't talk, pal. But if you can prove to me yours does, I'll give you a drink. If not, I get to kick your ass."
"Okay," says the guy. He turns to his dog. "Okay fella. Tell me -- what is on top of your doghouse?"
"Roof!" The man turns and smiles at the bartender.
"THAT ain't talking! Any dog can bark!"
"Okay boy. Tell me -- how does sandpaper feel?"
"Ruff!"
"What the hell are you tryin' to pull, mister?"
"Okay, okay," says the man. "One more question please. Okay buddy, tell me -- who is the greatest ball player who ever lived?"
"Ruth."
The bartender beats the hell out of the guy and throws onto the sidewalk outside of the bar, then throws the dog out next to him. The dog stands up and looks at the guy.
"Geez. D'ya think I shoulda said DiMaggio?"