We had a gsd gaurddog at work that was a complete tosser , could be in its run feeding it and if someone walked past who it thought was higher up in the 'pack' than you, it'd have you .. if you had it out in the yard and it stumbled upon you working without you seeing him he'd have you .. he was the most sneakiest wanker going , I could walk it round the village not a bother out of it soon as I got back to the yard it'd turn on me if it seen the night watch man FFS