[Onni]

I would never leave them alone for starters, and correct the Dobie every time he growls at her.

I have big dogs also and my little Onni is never left alone with them. My Jack Russell (the smallest of my 4 other dogs) was the most rambuntious with her and we made him submit by rolling over on his side any time he growled or acted like he was going to be rough. It seems to have worked, he plays very gentle with her now (under strict supervison from Mom and Dad) I do not even allow her to be around the big dogs unless me or my husband is in the room. She is not aloud around the big dogs with my kids.

Even when Onni is grown she will still be highly supervised around our other dogs. I think it just comes with the territory of having a Yorky.