Castration of dog

Question
I would like to know if there is any upper age limit to when a male dog can be castrated? My dog is 10.5 years old, mixed breed and middle sized (20 kg). He shows nervous behavior, separation anxiety and sometimes aggression towards other dogs. I was also wondering if a castration at this age would help him calm down and become more balanced?

Answer
There is no real age limit, it is determined by the overall health of the dog to undergo a surgical procedure. It would certainly not hurt your dog to be castrated at this age, but a lot of aggression is learned and not just sexual.

Some of these behaviors might linger for a while, some or all may just all disappear.
All you can do is go ahead with it as you have everything to gain and nothing to lose.
He does (his testicles), but he won't care!

This is the wisest choice. Get it done.