Quotes copied (selectively) from http://www.behaviour-problems.freeserve.co.uk/2/Fun/dogquote.htm (And a few other sources.)

A dog teaches a boy fidelity, perseverance, and to turn around three times before lying down. -- Robert Benchley

Did you ever walk into a room and forget why you walked in? I think that's how dogs spend their lives. -- Sue Murphy

Dogs need to sniff the ground; it's how they keep abreast of current events. The ground is a giant dog newspaper, containing all kinds of late-breaking dog news items, which, if they are especially urgent, are often continued in the next yard. -- Dave Barry

Ever consider what they must think of us? I mean, here we come back from a grocery store with the most amazing haul: chicken, pork, half a cow. They must think we're the greatest hunters on earth! -- Anne Tyler

I wonder if other dogs think poodles are members of a weird religious cult. -- Rita Rudner

I wonder what goes through his mind when he sees us peeing in his water bowl. -- Penny Ward Moser

In dog years, I'm dead. -- Unknown

My dog is worried about the economy because Alpo is up to 99 cents a can. That's almost $7.00 in dog money. -- Joe Weinstein

The great pleasure of a dog is that you may make a fool of yourself with him and not only will he not scold you, but he will make a fool of himself too. -- Samuel Butler

To his dog, every man is Napoleon; hence the constant popularity of dogs. -- Aldous Huxley

Whoever said you can't buy happiness forgot about puppies. -- Gene Hill

Women and cats will do as they please and men and dogs should relax and get used to the idea. -- Robert A. Heinlein