allinto learning is right in away. But just to explain incase you aren't english speaking. When a person is seeing another person it means dating. But it all depends on context. You could say "I'm seeing the movie at 2pm" or "I am seeing what you mean" (another way of saying understanding). In those cases of course it doesn't mean dating.
In the case of an animal and another animal, or an animal and a person it still doesn't mean dating, but it's not as commonly used. You could say "She is seeing the cats at the shelter today" and it's perfectly fine. But in this type of context it just doesn't sound right to say "the cat is seeing the person"