I wrote on here a couple of months ago about how aggressive my dog was to my puppy and the scraps and squeals that occurred regularly.  I got some good advice, one to ones with her, make her feel special, don't allow it to go too far but don't interfere too much, i followed all of these things, showed them I'm in charge and to a certain extent it worked. 

However, I'm sorry to say, its still going on!  As he (Lubo, 4 month old schnauzer) gets bigger, Poppy (3 year old schnauzer) is getting more aggressive and surly.  Lubo now gets 'shadowed' (she's like a bouncer) round the room and is made to sit in the hallway because he's too scared to try and creep past her.  In the past, his 'cowering' act worked and she tolerated him but now she attacks him at will (I say attacks, I mean goes for him, he has a couple of tooth marks on his back but nothing else).  He can't eat dinner without her growling, he can't have a drink, if he dares move she'll leap across the room with fangs bared.  So he's not eating anything!  Or he's waiting til lights out to creep in and try and get some food.  I can't even work out what or why she's doing it, i can't see any movements or trigger things like staring thats making her so worked up.  I do know that its much worse inside and in small spaces, out in the open it seems fine.

Any advice would be gratefully appreciated. 

x Jo x

If her behaviour is affecting him to such an extent that he can't eat or drink, then I think you have to use some manegment techniques so he can at least have uninhibited access to food and water for at least a part of the day.  It sounds like she has some SERIOUS resource gaurding issues going on, and I would recommend you get hold of a copy of 'Mine - a Guide to Resource Guarding' by Jean Donaldson