A civilization of elves, catfolk, dogfolk, merfolk, and other animalfolk; based on real-world humans, cats, dogs, fish, and other pets. Could it ever work?
You have the elves. They live in tree-cities, they like bows and wondrous magic, they have kings and queens, they have day jobs to pay the bills.
You have the animalfolk with far shorter lifespans. They are slaves in a way, yet extremely privileged and pampered slaves. Elves find them simply adorable and love to have them around as companions in the home.
Elves acquire their pets through either purchases or animalfolk husbandry. Many animalfolk are separated from their parents during their childhood, so that they can be given to a loving home, but a select few animalfolk live with their biological families under a single elven household.
Elves house, bathe, feed, and protect their pets, expecting more or less nothing in return. An animalfolk who lazes around all day and plays with toys (or, since these are sapient, engages in hobbies like book-reading and artistry) is par for the course. Elves love it when the animalfolk return the affection in one of many cute ways, from a doggirl cuddling up with her master, to a catboy presenting dead birds (hopefully actual birds) as murder presents.
Animalfolk generally love their owners for taking care of them. Some pets are eager to chat up their owners on all manner of topics, while other pets prefer to silently bask in their master's presence. However, there are a few despicable and abusive owners, who are reviled and often arrested by the other elves.
There are many kinds of pets. There are catfolk known for their aloofness and self-maintaining independence, the loyal dogfolk who are sometimes given legitimate jobs in elven society, the merfolk who live in schools in aquariums and do nothing but laze around, and more.
Elves love their pets so much that it is always a tragedy when an elf inevitably outlives their animalfolk.
How could this concept be refined?