I'm new here and have a Corso that has become aggressive

[mastiffpride]

Hi, I have a 1yr old Corso that has lived w/ my other 6 dogs since he was a puppy. Recently he started attacking my 2yr old intact English Mastiff. My mastiff used to back down, but now I think he is tired of it. He has fought back. Not a major fight a few cuts on the face, but it was difficult to separate them. I have an appoint. to get the Corso neutered on Friday and I have also purchased a shock collar and put it on the mastiff b/c he will stare at him occassionally and I don't want another fight. My assumption is the hole "pack leader" thing and the Corso is/was trying to get to the top and the mastiff has had enough. Any suggestions on what to do? Only those 2 have fought, every one else gets along fine. Advice would be great!

[Cohors]

What to say? you have guard dogs, this behavior is more than expected between males and mainly in a pack. The neuter won't fix the problem. If you can not live watching regular flights, divide all your place or think of give him to a good friend or a responsable family, it will be good for him cause he still youth and  will adapt fast, but please leave his balls- you are thinking in you and not in him doing that. Sorry if I looked arrogant and pessimist, but there isn't another situation to fix that. Don't spend $$ in trainings cause they will return soon or later flight again and more brutal.No books, no collars shocks and Cesar Millan, this is their instincts, truthful and basic.
Wish you luck