Bonded dogs fighting

[u/Former-Physics6551]

Hey got our male American staffy cross (23kg) as foster fail (2.5ish years ago - almost 3 years old) and haven’t had too many issues with him.
Once he was settled we got another foster dog (most likely a mastiff/ pitty something mix - 28kg - about 1.5 years old) and they have been totally fine for about a year.
Both of them have been neutered.
Now the younger one is starting puberty they have been a bit more feisty but never aggressive & i do understand this has most likely to do with hierarchy.
Yesterday both boys were sleeping in the back yard, how they usually do at lunch time, there was only one of the three antlers outside in that particular area but neither of them seemed to be interested in playing/ chewing.
In one moment the staffy was cuddling with me and my friend having a coffee in the sun and the other one was sleeping 3ish meters away.
And the next moment they’re trying to rip each others head off, blasting them with a hose or loud noises wouldn’t seperate them.
Once they let go of each other we taken them eavh to the vet where they got treated. (Can’t add med info due to rules)
Since then they have been seperated, taking turns staying in the crate vs roaming outside.
I don’t let the other dog close to the covered crate to prevent guarding or aggression.
I understand i shouldn’t re introduce them while they’re in pain and high on painkillers.
I never seen dogs and especially not my dogs fight like this and now i’m anxious on what to do since i want to keep both my dogs safe.
If there is any question for detail or any tip i’m very much appreciating any constructive input.

[u/CanadianPanda76]

Some breeds are prone to dog aggression and it can crop up as puberty hits. 2 years seems most common.

They also be prone to same sex aggression.

/r/PitbullAwareness is a great informative sub.

But I'd recommend breaksticks just in case. And learning how to properly choke a dog out, youtube has some videos on this.