Big Paws Only Dog Forums

I have a one year old male Malamute, who is very dominant and aggressive towards our other 5yo golden retiever. The malamute grew up with the other dog and recently started being aggressive towards him 4 months ago. I had him fixed, but the bahvior is so bad that we have to constantly keep them seperated or muzzled...any suggestions would help! I would love for the two brothers to get along!