What does it mean when your female dog is panting whining and acting strange?

Possibly she is in heat and wants to mate.If she's pregnant , she's going in to labor. If she's not pregnant, check her over gently for wounds or a piece of glass in her paw, something like that. Be very gentle and be careful she doesn't bite you . Some dogs get aggresive when sick or in pain.If you find nothing, call the Vet. It may be something internal.And don't wait til morning.