Verified answer

Only certain animals like eagles can look directly into the sun. others like farm animals can be seriously effected by looking at the sun

To answer your questions, in order: Yes. And: Yes. They have sunglasses for pets, but I don't think they make them for larger animals. If you have anything larger than a dog I guess hope it's smart enough not to look directly at the sun.

Well, they can, but it hurts their eyes!

of course it hurts their eyes, that's why they have pupils