The only exceptions are true guard dogs and actual cattle/sheep herding dogs. They work for their perks. (Maybe some show dogs, too, if they earn money, rather than just ribbons.
Service animals (e.g., dogs for the blind) also generate wealth in an indirect way. I have a blind neighbor who is a corporate attorney. He travels by bus every day with his guide dog. So in a sense, the guide dog generates revenue in that he allows my neighbor to go out and earn a living.
But I will say this, even though our pets may not generate money per se, what they do give us is often far more valuable.
See my posts #24 & 37. I was just kidding and forgot the smiley winky face in my first post about all that..