We have a tiny jack russell x chihuahua (she's only 7 inches high bless her) and one large gsd girl and one enormous gsd boy, as well as 2 whippets and a jack russell. Guess who rules the roost!!! Teeny, tiny little Midge bosses the big ones around. If you were to throw a single treat to all 6 dogs I would put my money on who would get it first I must admit though that we don't leave her in with the big ones whilst we are out, just in case they decide to get their own back on the little bully