try garlic rosaries on the door handles … seems to work with mother in law…
We now never feed ours liver after a serious of unfortunate effects( and a lot of cleaning up the mess).
Not sure about Shepherds as ones I've known like to bark on principle just to watch people jump. Best thing I ever did was buy loads of tennis balls ( ex tennis club) as they still have a lot of bounce ( as do the collies) and ,with a decent ball thrower, make walkies really fun. Still have to watch 'em as the art of "Poo rolling" is a favorite trick. Fox poo it seems is a great delicacy as merits really rubbing it in. Needless to say the bath room needs a good clean, as the dog(s) sulk.