A man is walking his dog, and passes a little restaurant; the cooking smells are so tempting, he decides he would like to stop for lunch, but the sign says no animals are permited.  

After a couple of moment's thought, he decided to brazen it out: he puts on a pair of sunglasses, walks into the restaurant, with his dog on a leash and asks to be seated. The waiter says "I am sorry sir, but we do not permit animals in the restaurant."  

The man says, "But I'm blind, and this is my seeing eye dog."  

The waiter responds skeptically: "Your seeing eye dog? Sir, that dog is a Chihuahua."  

The man responds: "A Chihuahua! They gave me a Chihuahua?"