Need help with sudden and sporadic aggression between our males.

Hi folks
I'm hoping you folks can help us. we have been experiencing sudden and sporadic burst of aggression from our 2 year old catahoula, towards our 12 year old great pyrenees. There are no identifible triggers, and when we attempt to intervene, the 2 year old redirects his agression towards use for a few mins. Most of the time the 2 year old acts friendly towards the 12 year old. However the 12 year old is leary of the 2 year old and steers clear. Just recently the 2 year old came running up from the yard onto the porch to go at the 12 year old, who was just being pet by a friend who was over. When I intervened and put him on the ground he still growled at me for a few secs until I let him up and crated him. Mind you the 2 year old had just been being pet by the same person and decided to leave out to the yard. There doesn't seem to be any theme to this, no re-occuring place, activity, or individuals involved, except the two males. the 2 year old shows absolutely no aggression towards any of the other animals on the farm, or towards any people (with the exception of the redirected aggression during an incident). does anyone have any incite or advice on why this may be happening, or how to correct this.

Has your two year old been neutered? If not, I would try that. At Two he has probably just reached maturity and is trying to establish his dominance. Despite his size, your Pyrenees needs to feel you will protect him. Don't leave them alone together and monitor them to head off any problems. I would certainly crate him when it happens. Putting him on the ground may only escalate the redirected aggression. Try to remain calm and use a firm tone when redirecting him. If it continues, you may want to consult a behaviorist. Good luck.