Dogs Fighting

Question
I have two dogs- they are siblings,a female and a male,  Boerboels and not yet a year old.
They have been completely fine with each other until lately when they have started to fight
The fights get quite viscous and they have bled slightly, it is very hard to break them apart, even with water, and my maid's hand was bitten yesterday when trying to stop a fight
The female recently got spayed, but the male is not neutered.
What could be the possible cause of this and will it stop eventually? My mum wants to separate them but I love them both so much and cannot bare with the thought of having one of them gone
We spoke to our vet but he was not helpful at all and just said to "let them work it out themselves".
Is there any way they can get over this? Or will we have to move one of them to a different home?

Answer
Greetings, and thank you for contacting All Experts!
Any chances you can provide more details on the dynamics of these fights? When do they occur exactly? Is there food, toys, bones around? Do they happen around family members? Are they barking at something in the yard and then they fight? More details about the exact triggers would be much appreciated so I can provide a more detailed answer. Thank you!