My airedale Chanel is also very protective, she's starting to become very aggressive around my golden Ema who's 3. Last weekend my dad was sitting down and Ema was up on his lap, for fun he started squealing like she was attacking him and Chanel came running over to them, jumped right up on the chair with them and lunged right at Ema with a snap, she didn't bit her, she just threatened to, then she backed off slowly without taking her eyes off Ema. She's been doing this lately, hopefully she'll realise who's boss (Ema, hehe). Thanks for all of your replies. I might get a good pic of Chanel up soon.