A stranger enters a store and spots a sign: DANGER! BEWARE OF DOG! Inside, he sees a harmless old hound asleep on the floor.
“Is that the dog we’re supposed to be aware of?” he asks the owner.
“That’s him,” comes the reply.
“He doesn’t look at all dangerous to me. Why would you post that sign?”
“Before I posted that sign, people kept tripping over him.

And a bonus joke!

A poodle and a collie are walking together when the poodle suddenly unloads on his friend. “My life is a mess,” he says. “My owner is mean, my girlfriend ran away with a schnauzer, and I’m as jittery as a cat.”

“Why don’t you go see a psychiatrist?” suggests the collie.

“I can’t,” says the poodle. “I’m not allowed on the couch.”