We have a 3 yo Cav King Charles, who has a lovely nature 99.9% of the time. Sometimes when we give him some of his doggy treat biscuits he wolfs them down straight away, but sometimes he doesn't and this is when he becomes a nightmare! He can sit and guard these treats for hours - if you walk past him when he is guarding them he will growl at you, and run up to you and bite your skirt, trouser leg, hem of Tshirt etc. He has never bitten us. He gets so tense it is unreal, sometimes he sits shaking with his nose about 3inches from the biscuits just staring at the bloody things - he can't possibly get any enjoyment out of them like this, and his reward for being a good boy leads me and my 11yo son to walk on egg shells when he is like this - my son is genuinely scared to walk past him, say to the loo, when Will is behaving like this. On occassion I have picked him up and took him to another room while my son puts the biscuits in the bin, and he growls really strongly and i think if i didnt hold him at arms length he might bite. I dont want to stop giving him the treats - as I say he isnt like this everytime. Any advice for dealing with please?