Barking dogs!

One issue Radar is slow to resolve is barking at other dogs. Every time we meet a dog out on our walks, Radar barks like there's no tomorrow! For a dog that's only 30 lbs, he has a deep bark, too. It sounds like he's wants to eat the other dog, the way he goes, "rrrr . . . ruff, ruff, grrr!" I'm a little afraid he's getting the Mailman Syndrome, where he barks at the other dog and it walks by us, so he thinks he had something to do with that!