Oh I have one but it's fairly long.:
Two men were walking their dogs together when they decided to stop for a beer. A sign outside the pub said ' No Dogs Allowed".
The first man promptly pulled some dark glasses out of his pocket and walked in with his dog, a border collie.
The bartender said: "Sorry you can't have dogs in here"
The man replied "Oh, he's my seeing eye dog"
The bartender apologised and let him have a drink on the house.
The second man had been watching this and pulled out his glasses as well. He walked into the pub with his dog and proceeded to the bar. The bartender said "Sorry, you can't have dogs in here"
The man replied "Oh this is my seeing eye dog"
The bartender scoffed and said "Sure, your seeing eye dog is a Chihuahua"
Without missing a beat the man exclaimed " WHAT? THEY GAVE ME A CHIHUAHUA??"!"