The war dog is quite useful. Not only can it attack and kill enemies, an archer can best utilize a dog to distract his targets. Just try not to shoot your dog in his pooper. Now if I can only get him to muzzle up!
Are you using Barbas? If you are, he isn't meant to be a permanent follower, he is only supposed to be used during his quest. But really, followers making noise and being loud isn't exclusive to dogs, all followers make random statements at the most unfortunate times.
I don't know about you but I sure as hell wouldn't stop barking if I'd just had an arrow shot up my arse !?!?!?!?! --- "That would explain how she died. It wasn't old age; she just roundhouse-kicked herself in the back of the head" - ShadowWraith666