I'm going to give my friend advice on how to raise his dog.
I'm wondering what kind of advice you want to give him about his dog?
I think he should give him something hot to eat after playing with him in the snow.
It's a good thing to give someone advice if they ask for your help, but they may get annoyed if you give unsolicited advice. Giving help when someone didn't ask for it makes it seem like you think they are incompetent. That could cause tension in your friendship.
It's not like he asked for advice. I was just offering.
Offering your advice to someone out of the blue can be a nice thing, but if they didn't ask for it and seem to be happy then it could annoy them. How would you like it if someone went around telling you how to handle your pets?