Has castration made my dog aggressive?

I had my 3 yr old male staff castrated 2 weeks ago. Today was his first long walk since the castration and he became really aggressive when a dog approached him. He is not normally aggressive and normally tries to play with other dogs. Any advice please?!

i think he will still have hormones in his system, i'm sure someone said they can have for like 2/3 months so it could be that. give him time & make sure he know what right and wrong

I think it would take me a while to get over being castrated aswell

He's probs not feeling himself like steve said it,ll be down to hormones

After castration a dog becomes more aggressive at first.....this is due to what he has been though and feeling more vunable than normal so it is aggressive to get in there first and warn off any dogs.
He should start getting better as he starts to settle back into normal life

Yes, he'll be feeling unsure of himself, so getting in the first blow. Let him know it isn't acceptable & hopefully he'll come round once he's settled a bit more.

Keep an eye on other dogs' reactions, though. A newly castrated dog seems to give off a strange scent & some other dogs react agressively to it.