For a wild animal, the default state is health. In normal times, wild animals are an appropriate weight. In the wild, animals don’t become obese. They don’t become depressed or suicidal. They don’t exhibit behavioral disorders. Animals inhabiting their evolved, ancestral environment are healthy — by default.

I disagree, animals starve if there are too many due to overpopulation and will get fat if they find an easy source of food. They often die from infections, collect tons of diseases, have many parasites.

It's easy to see animals be sad and mourn the loss of a pack member or child in certain species.