
I am using Suprelorin on my hyper dog and it has calmed him a little but not stopped his rushing into his kennel mates the only thing that works with that is a radio control Master collar. So no I do not think removing the testosterone will stop his aggression, castrating the other one may help so try treating the calm one with Suprelorin.
He is just coming up to requiring his next dose and I am not looking forward to it, last time it took 3 vet nurses a muzzle and me to control him enough to get the dose in and bless him the vet apologised and said he hoped he could do a better job next time.