It's hard now to imagine morality without the ideas of reform or progress, which seem out of place for animals.

You'd like to be able to say that the difference between a good dog and a bad dog matters to a dog. To other dogs.

Or that the difference between a good bird and a bad bird matters to other birds.

Harder to say would be whether it matters to a dog or a bird whether it is a good or bad dog or bird. Or whether that amounts to the same thing as its mattering to a dog or a bird whether its being a good or bad dog or bird matters to other dogs or birds.

Can animals ever be hiding something?

It's interesting to try to think of animals acting, not for the sake of the good or the right, but of 'the fine'.

It seems as if animals might naturally have 'strangers'. But friendship?

It's difficult to imagine a third animal party stepping in; at least one which isn't dominant.

Is there a sense in which animals are ever expected to answer for anything?

Coming when called, and answering to a name, are not the same.

Though few will do so, it's possible not to give your pet a name. Not giving a child a name is unthinkable.