I have a 2 year old Labrador. Up until a few months ago, he was perfectly friendly with all dogs (bar none). But since he turned 2, he is very aggressive towards any and every, Male mature dog. Totally fine with bitches, Male dogs that have yet to hit maturity, and male dogs that have been castrated. This to me, seems to have something to do with the testosterone male dogs give off. It's not even just if he comes close to another dog. We could be 50 metres away & he will already be barking or growling. So my question is, would castrating my dog. Help this behaviour.