my dogs hate each other

Question
Hi

I have 4 dogs, a saloki mix, labrador, german shepard and a huskey. All get along except the saloki and lab. The saloki is around 17 yrs old and the lab is 10. When she(lab) was a pup they were fine together even when (saloki) pick on her. She was small and used to take it. As she got bigger it got more dangerous to have them together as she is much stronger and bigger in build than him. They would fight on who is the leader. We have now for yrs kept them apart. But if she would get the chance to snatch him she will go for the kill and he doesnt even budge. He doesnt run.

I know that its probably to late to fix the situation but i would like to understand why they have this problem. She is unbelievably sweet and has no problems with other dogs and the same goes for him.

They have gotten in a few brawls where i have had to get between them which has been dangerous but i can not have her kill him as that would mean i would loose both of them. The Shepard (she) will help the lab is she is around in the fight. Which does not make sense to me as they get a long brilliantly.

Could you maybe help me with understanding this hate between them?

Is there a chance that they could be friends. She is very much a leader and he is extremely stubborn.

Thank you

Sara

Answer
It is likely both were dominant in their litter and want to be dominant in your household.  In rare cases, there is no making them get along.  This seldom happens, but when it does, it is most likely 2 females.  I don't know if you can correct the situation or not.  Many good people have ended up rehoming one dog.  

I observe my daughter's dogs.  She has 3 neutered males.  The little terrier mix continually challenges the Shepherd,  but gives up after one snap from the Shepherd.  Some dogs will never give up.