Okay guys, I would like to nip this behavior in the bud and need advice for the best way to do it.

Gus is growling everytime he hears a noise. Even CoCo has no clue why he is growling. I'm pretty sure that he is just settling in since we got him home a few minutes ago and he is still trying to figure out things.

I just want to make sure that I show him immediately that this behavior is not acceptable, but I want to make sure that I am teaching him the right thing and going about it the right way.

Everytime he has been growling, I have firmly been telling him ENOUGH, and the moment he stops, giving him a treat and saying "good boy" The thing is, he really keeps growling after a second and he is very hard to stop.

I'm sure he will settle down, but I really want to do this right for all of our sakes.