I recently read this one somewhere - maybe on someone's signature here?
"A dog is man's best friend, but a little dog is a woman's constant companion."
This one I have a cute crafty thing I got at a fair hanging where I feed my cats: "Dogs have owners, cats have staff." I guess that's more of a "cat" quote, but I love it
Funny one I heard:
"Don't accept your dog's admiration for you as conclusive evidence that you are wonderfull" LOLLOL