You may want to request the two threads be merged.
Here is a link about various homeopathics...choose what serves the most likely scenario - outside of the obvious sudden aggression.
I would guess this is probably a newly learned behaviour compounded by an imbalance in hormones (adrenals). Question is will it regulate back to normalcy?
So along w/homeopathy some new rules/boundries have to be set.
You'll have to scroll down for the recommended list that matches other conditions
False Gestation and Nervous Lactation
He is your friend, your partner, your defender, your dog. You are his life, his love, his leader. He will be yours, faithful and true, to the last beat of his heart. You owe it to him to be worthy of such devotion. - Unknown