is there any way to get 2 males back together they have got along for 3 years and now they just want to fight they are father and son

NO NO NO!!!!
Don't attempt it, the WILL kill eachother without a doubt. When male Dobes start fighting they NEVER get along again. I have been there, know many people that have too, a child gate between the living room and the kitchen and dining room was the ONLY way I could keep my dogs within a few feet of eachother.
Dawn.

Have to agree with Dawn on this one.

Have a friend who breeds dobes, they are notorious for not being forgiving in any way. Once they have started to fight they is no way back other than keeping them apart.

I have had a similar thing years ago with two BT's who had lived together in perfect harmony until one was 7 and the other one 6, a small spat caused by another dog at a show sparked them off, and although most of the time they were OK, anything could start them off and in the end I had to rehome one of them.

By the way I am totally the boss in my house, the fights use to happen when you least expected it, so there was no way that you could forsee the situation happening.

I take it the son is trying to assert himself over the father?
You will have to be very careful and not give them the opportunity of fighting such as using a muzzle or keeping them separate.
I just posted something similar to someone else but the same sort of thing applies. Treat the son as top dog and ignore the father for a while as they will be changing positions in the rank structure. Yes, it can be done but it takes time, patience and consistency. Eventually, when the younger dog becomes comfortable with being the canine leader in the household, then the father won't become as much as a threat and you can start to interact with him again, starting off slowly but if the younger dog intervenes then shift your focus back on him.
Keep up with asserting your own authority over the pair of them. You are the boss!
It may take a long time so be prepared to look out for their safety and you may never be able to totally trust them and leave them unsupervised.
I have been through it with GSD's and from the merest eye contact sending them into blinding rages and trying to kill each other - they now seem almost fond of each other and spend hours seeking out each others company and interacting well together. However, having said that - I never ever leave them totally alone (just in case!)
Lara x

With respect Lara, GSD's are NOT like Dobermanns, once they start they NEVER stop.
Dawn.

No offence taken :). I never say NEVER.
Lara x

Where there's a will there's usually a way.

Hi guest, I was quite surprised to hear that they've managed to live together so harmoniously for three whole years! That's an achievement in itself & I think you've done well so far. But I think the others are probably right in summising that you won't be able to trust them together from now on. Dobes never forget a grudge do they? Once they form the opinion that they don't like a dog it doesn't matter how long they spend apart - they always remember and are up for a fight the minute a challenge presents itself. A dog gate really does sound like the only solution from the little you have told us.

My dobe was introduced to my sister's Siberian husky a year ago, they were both a year old, just pups really. They played happily for half an hour before the almightiest dog fight broke out much to our astonishment. It's the only true dog fight Hugo has ever got involved in & I was absolutely devastated when it was obvious that the husky required vet treatment. I knew from that moment on that I would NEVER be able to trust Hugo with ANY other unknown dog ever again. It's a massive truth that I found extremely difficult to accept - we all know what absolute softies they are in the home and it's at such odds with how agressive they can become when challenged. Quite by mistake, one year later both dogs met up again at my mother's one day and they were snarling the minute they clapped eyes on each other from a distance of 50 feet.

I'm sure you love your dogs & I'm sure you don't want be naive about the situation - it has enormous potential to end in absolute disaster, serious injury or death.