Lily sounds like she has resource guarding issues. We've dealt with a numberof fosters who have this and it can be very frustrating! One thing a behaviorlist told me was to remember that growling was a way they dog was communicating his displeasure. We had one that would go after us whenever we tried to remove the item...usually one of the kids' dirty underwear he managed to snag! :roll: Within a couple weeks he would still growl ('cuz he didn't want us to take it) but there were no more aggressive movements on his part. We just let him communicate his annoyance (because we all need to grumble) as long as there was no aggression.
Of course you have the addded issue of Rosie coming to your defense when Lily growls at you! I would certainly do as you are doing and get in touch with your trainer. My dogs have only reacted this way to 1 other dog. I had to put mine in a sit/stay before I could attend to the other one. Made for quite the circus!
Here are a few links to resource guarding (you mayhave already found these)- just various info:
Guarding and Showing Aggression Over Resources
Resource Guarding
Why does my dog guard food, toys and beds?
Nothing in Life is Free
Of course you have the addded issue of Rosie coming to your defense when Lily growls at you! I would certainly do as you are doing and get in touch with your trainer. My dogs have only reacted this way to 1 other dog. I had to put mine in a sit/stay before I could attend to the other one. Made for quite the circus!
Here are a few links to resource guarding (you mayhave already found these)- just various info:
Guarding and Showing Aggression Over Resources
Resource Guarding
Why does my dog guard food, toys and beds?
Nothing in Life is Free
