I have never liked zoos. To me, they are prisons and do not provide healthy environments for the animals locked in small places (relative to their natural habitats). Suffering does not have to involve physical pain or torture. For animals, like chimpanzees, who have highly developed emotional and intellectual brains, suffering can be severe merely because of captivity.
Here is a truly heartbreaking example of how bad zoos are. I can barely look at it.
Something should be done to provide healthy sanctuaries for those wild animals that we have taken into custody. Zoos are not sanctuaries.