So Chloe has decided to be a dingle berry and attack Rose whenever Rose comes inside through the front door. I'm not sure why all of a sudden she feels the need to do this, but this is Chloe we are talking about. After breaking up two fights and preventing a third, Rose is no longer allowed in through the door with Chloe inside, which is a pain in the rear as she has to come in through the back door. Chloe's always been a bit of a brat about that. When she was a pup and Blackie and Rose were outside dogs, if I had Chloe outside and went to let Blackie and Rose out of their kennel Chloe would growl/lunge/nip at them whenever they would pass through the kennel door. It got worse, but once she realized I was NOT going to tolorate that (I'd "Hey!" in my meanest voice and lunge at her - she'd belly drop) she snapped out of it pretty quickly. I had noticed that she tends to send aggressive signals whenever Rose (or any other dog, really) would walk into the house - tail up, closed mouth, maybe a barely audible growl - but I could just say her name and/or split between her and Rose and she'd stop so I didn't think much of it. Now she just full blown attacks her. They get along fine otherwise (if there isn't a food resource around) and if Rose is in the house first before Chloe comes in, or they come in at the same time, there isn't any issue at all. They hang out together and all that jazz without any problems. Rose ignores Chloe, but she doesn't back down to her either. So I know it isn't Rose starting something, but once something is started it's on. I'm assuming I can desensitize Chloe to this by letting her nibble on a treat whenever we go to let Rose inside? (She'll do anything for food.) Or is something deeper going on than I realize and I need to do some major rehabilitation? I just want to nip this in the bud before animosity develops and they can't even be together.