Well, MLP fans aren't necessarily furries, and just as well furries aren't necessarily MLP fans. Bronies might just like mlp, but not like anything else that could be considered "furry". Most bronies, from what I remember about a brony poll, don't identify as bronies.
That said, MLP is a show about talking animals with some human characteristics.
As such, it can be said to be part of the furry fandom.
Just don't expect all bronies to be furries or the opposite.