Hi, I've seen a Dobie bitch with many hard white spots on her chin and lips, which i am told are as a result of acne. A friend posted this query on the forum and the suggestions were applying aloe vera gel, and washing the chin after meal times. Hope this is of some help!
I had a dobermann who live until he was fourteen, he pasted away about five years ago, at an early age he suffered alot with acne, he'd get spots on his chin then they would errupt or he'd knock them and they would bleed. I'm not sure about acne in the mouth though, maybe someone else can give you more information. It might be a good idea to pop her along to the vet and get them checked out. Are they like pimples? what colour are they? are they in clusters?
Warm regards susan