If our friend makes the potion right, he won't have to keep away and he'll be as docile as a puppy.

[ Oi, listen here, you. It takes a lot of magic and a lot of control to be an Animagus, and to become one at Sirius' age is a serious testament to his abilities. I guess some people can't appreciate pure talent. ]

And you're talking to the heir to one of the oldest and most powerful wizarding families in Britain. If you think you've been at this game longer, you might want to look at my family tree.
[ uh oh, voice rising ] You're lucky I didn't tear you apart, you overgrown dingo. The only reason I didn't was because you had a damned knife on him.

Well, then. Maybe in the future you want to teach your charges to stay away from the forest, eh?