Sargent and I play tug-of-war almost on a daily basis and he just loves it. He's only still a pup but I think the difference is that you must teach them to distinguish between 'playing' and not 'playing'
If Sargent growls when taking something off him, then a stern 'NO' will make them realize that its not a game. But when its playtime, then its ok to roll around, growl, and even bark a few times, all in the good light of playing and sharing quality time with them. This disables any acts of growling when perhaps taking something away from them, like their food bowl. He's learnt, that when mum or anyone takes something away, whether it be food or something else, its ok, and he steps back and waits. But when its playtime, he doesnt have to..hee hee..even though mum always turns out to be the winner, I always let him take the toy away and have a good chew. It works wonders for Sargent. They've just gotta know when its ok to growl while playing, and when not to. Good Luck
