After a while, the man and the German Shepherd get up to leave. As they're going out the door, another man with a Chihuahua is coming in. First man says, "The bartender won't like you bringing that dog in here, but just tell him it's a Seeing Eye dog and then it'll be OK." Second man looks dubiously at his tiny Chihuahua, thinks a fews seconds, then thanks the first man and goes on in.
Bartender says, "Hey! You can't bring that Chihuahua in here!" Man stares straight ahead and exclaims "What! They sold me a Chihuahua?!"