Use stainless steel bowls if you don't already and wash them after each use. Keep his face as dry as possible. I used apple cider vinegar with the mother as a wash. Hormones seem to wreak havoc in some dogs just like in some teenagers. Ella had horrible acne until she was three years old and it always flared up right before her cycle.
Just a note on the tea tree. Tea tree oil should not be ingested. It's considered toxic and not intended to be used anywhere near the mouth. Any use of essential oils on pets should be done very cautiously because animals metabolize and react differently to them than humans do. Cats are particularly sensitive. If you choose to use it in an area where it can't be licked, it should be diluted in a carrier oil. It *is* very effective for acne and fungal issues, I just would not use it anywhere where ingestion is a possibility.
