I agree... you shouldn't try to get too complicated.

So... Why not just copy real life... vis-a-vis humans and pets. Most everyone loves their pets and would never think of abusing them.

This allows for all kinds of hot story lines... and the occassional mis-use... (and rescue?) story. Pets can be treated like dogs or cats or horses (ponyboy/girls) or exotics.

Alternately... but along the same line... make it a slightly sci-fi setting. Two races physically similar but the superior race communicates telepathically... and the pets don't. In addition to all of the above story lines... you can add all kinds of breeding programs. Breeding for behavior, physical attributes... etc.