A man with a Doberman Pinscher and a man with a Chihuahua are out for a walk. The man with the Doberman suggests, "Let's go to that restaurant and get something to eat."
The man with the Chihuahua objects, "We can't go in there. We have dogs with us."
"Just follow my lead," replies the man with the Doberman.
They approach the restaurant. The Doberman's owner puts on a pair of dark sunglasses and starts to enter.
A man at the door stops him, "Sorry, mac, no pets allowed."
"You don't understand," says the owner. "This is my seeing-eye dog."
"A Doberman Pinscher?" asks the doorman.
"Yes, they're using them now. They're very good," he assures.
The doorman is convinced. "Come on in."
Seeing this, the man with the Chihuahua thinks, "Hey, why not?" He also puts on dark glasses and attempts to enter.
Again, the doorman intervenes, "Sorry, pal, no pets allowed."
"You don't understand," the man insists. "This is my seeing-eye dog."
The doorman looks skeptical. "A Chihuahua?"
To which the man exclaims in mock surprise, "You mean they gave me a Chihuahua!?"