Good Morning and welcome to Just answer. I am Dr. Loretta, a licensed veterinarian and I am happy to answer your question.
I am so sorry that your dogs are having this trouble. This is most likley due to a dominance issue and this causes extreme anxiety. The treatment for this is as follows:
Keep them separate for 1-2 weeks while feeding them and letting them out separate. Place a DAP Collar on both dogs which is a canine pheromnone that acts as a cakming agent and will decrease this anxiety. After the period of separation, take them out together on leashes , giving each treats when they behave and praise them loudly when they do teh right things. If there is any sign of aggression, carry a coke can wth pennies and when you see thsi baad behjavior, shakle the can loudly and say a strong NO! They will get the idea.
Your vet has stronger meidcations to help if this is not enough....2-3 weeks on the meidcation is usually enough to get them past this aggression.
Does that make sense to you?
Please let me know if you have ANY other questions. My goal is to give you 100% satisfaction and if you are not yet satisfied, please Reply so I can clarify for you
Sincerely, Dr. Loretta