We chemically castrated our male at 12.5 months because from about 10 months he became aggressive towards other males, he would regularly provoke fights and he got bitten several times. It was difficult to intervene quickly enough to prevent a fight because the situation could change very suddenly. Apart from male vs male aggression we didn't have any other problems, no humping, but he would occasionally mark indoors in unfamiliar settings if he could smell other male dogs. I agonised about it for a while because obviously don't want to him to suffer health problems later in life from lack of testosterone. But I also didn't want the aggression and fear around other males to become entrenched, or for him to be injured or to injure other dogs. He is now 16 months so it has been about 4 months months since he got the implant. For the most part it has worked quite well, we can trust him to play well with other males now. There still seems to be some residual fear that can cause him to react aggressively, such as when he feels encircled by two or more dogs, or when we pass a small dog on a leash who fires up viciously at him. But now it is predictable and manageable, we watch his body language and unless if there's more than one other dog that were not familiar with, we move on and he is usually quite happy to exit the situation too. Not much I can do about snarly, vicious small dogs on leashes but I hope with maturity and experience, he will learn to find them non-threatening. He has gained about 1.5kg from his pre-castration weight of 23kg, and has become noticeably more interested in food. This has actually made treat training easier, and he's made a lot of progress over the last 1-2 months with walking in a heel, not jumping on passers by and being more trustworthy/less destructive at home.
