my rotties would howl all the time all at the same time... it was hilarious because my pug would make an attempt to howl with them but it sounded dreadfully painful the way he'd do it..lol.
We could make a siren noise and get them howling at any given time. I would just sit back and laugh hysterically at them because they'd be so dang cute with it.
Lola has never howled... not even once! I have tried to get her to howl but she hasn't got a clue..lol. I guess she won't be a howling kind of dog. Oh well, I love her just the same.