I also used to have this conundrum about the zoo. And about eating meat. Also about all the dead pets I'd see on the side of the road and wonder why there were such horrors. But I have resolved this for myself to my own satisfaction through my chats with spirit asking questions and listening for the answers (and writing it all down in me handy dandy notebook)...

This is my

Every spirit is eternal including animals, plants, etc. So there really is no finality as death, just transition. That is one thing that helped me feel better.

Also, I began to understand that with reincarnation, an amazing array of experiences are incurred, and meant to be incurred. In some lives we have been the victim and in some the perpetrator. It's all about collecting knowledge, more so than experiencing only the easy, pleasant, paths.

This is the part about the zoo though, and about pets and wild animals in captivity...If an animal chooses to incarnate, it can have a life that is "normal" living in the wild being born, acting on instincts, reproducing, most likely becoming food for another animal, in rare instances dying of old age, or whatever. But if the spirit of the animal wishes to progress (and I believe that is the underlying desire of all because that is God's will) then to experience a life far removed from "normal" is an amazing consciousness expansion experience! To be amongst humans, no matter what some humans think of other humans, is to be amongst beings that have developed consciousness in a progressive and unique way. Even if some other entities are more developed like whales or dolphins (I dunno if they are or not, just sayin) it doesn't matter. A life lived with humans in the capacity of pets (because that is basically what is available) is a special life and great opportunity. So whilst animals in the zoo don't have ultimate freedom in this lifetime, they have traded it for a unique opportunity to live amongst humans. They have the stress of confinement, but not the stress of starvation. It's all trade-offs for a myriad of consciousness experiences. And maybe they really love it and relish it. Surely some of them do. (I shall simultaneously post about "Freedom the Eagle" as a beautiful story of human animal synergy).

It is amazingly healing and enlightening for humans to be in the presence of these animals and work with them. And visa versa.

Finally,

I believe that life is predatory and that this is a reflection also of the spirit realm in which one thing feeds from another endlessly. Everyone has a turn on top and on bottom and from every angle in order to understand and appreciate the entirety of existence. So enjoy your turn as eater or food, keeper or as kept, wherever you find yourself.