Do bulldogs have hair or fur?
Hair and fur serve the same purpose: to keep the animal warm.
They both refer to the same thing only hair usually refers to
sparse/patches of hair rather than a thick coat of it. We as humans
usually use the term "fur" to refer to the hair of an animal and
use "hair" to describe our own, or hair/fur that is sparse. In the
case of bulldogs the fact that they are animals would mean that we
would refer to their hair as fur although both hair and fur are
basically the same thing.