2 pets beginning to fight

Question
I have two mixed breed dogs. One is 8 years old and one is about 2 years old. They have lived together for about a year and a half. The younger dog is submissive and friendly the older dog more cautious with strangers and not friendly to other dogs. The older dog has been the dominant dog but now for some reason she has begun to attack the younger dog. The younger dog never begins the fight, but does aggressively fight back when attacked. I don't know why they have begun fighting, but now after reading some info,  I fear I have handled it wrong by separating them and punishing the older dog. How can I stop this before one of them is badly hurt and so they can live together again?

Answer
I would suggest that you find a qualified behavior consultant in your area to evaluate your situation in person. Try www.ccpdt.org or www.apdt.com and make sure that they are knowledgeable aggression.

Punishing either dog will not (as you know) make things better. In house fighting can be many things. In general you want to identify the triggers(are they competing for status? Space? Food? You?)

Train for incompatibility and manage the behaviors that cannot be extinguished through training.

A big line in the sand is "Are they fighting only in your presence or are they fighting when you are not there?" If they are only fighting when you are there, that can be fixed (most likely) if they are fighting amongst themselves they will always have to be watched and managed.

As your younger dog becomes an adult, things are becoming tense. Be sure to mention that to the consultant when you find one.

I hope all goes well for you and your dogs.