My friend and colleague, Dawn Baumann Brunke, is an accomplished writer and soul seeker. We've collaborated on a series of middle grade coloring books called Who Lives Here?, which I'm looking into having re-published. Meanwhile. Dawn's been exploring how humans can connect on a deeper level with animals through her "Animal Voices" book series. Some of the material delves into dealing with animals' pain and how they deal with it themselves, which is something many people wonder about, whether their pets are "almost perfect" or not.
You might want to learn a bit more about Dawn and her work. I think you'll be fascinated.