Don't worry, I'm sure it's just a scuffle. I had the same exact problem with Lucky (resident dog) and Giselle (new). Since Giselle was so thin skinned, I was terrified of even letting the two meet each other. It didn't make sense to me, either. Giselle was and always has been an extremely submissive dog. Whatever it was, those two dogs had multiple scuffles. At one point, Giselle couldn't even be in the same room as Lucky because she was so darn scared of him. It was SO heartbreaking. Giselle would sleep on my bed with one eye open. Whenever Lucky stumbled into the room, she bursted up and tried to jump onto my desk trying to run away from him. All through that horrific month, I kept in close contact with my adoption coordinator and I called her every few days to ask for her advice. I also e-mailed her continuously until things started to improve. Throughout that month, I kept wondering if I should give Giselle up....I seriously wanted to call our adoption coordinator and ask her if giving up Giselle was an option. Well, I gradually introduced them and made time together FUN FUN FUN!

I've learned to cope with Lucky's resource aggression and they are always fed at least 30 feet away from each other (different rooms in the house). Toys are never given without my supervision, and they've learned to tolerate each other. Soon, I'm sure they'll be content with each other's company. I've seen them snuggling from time to time I wish you good luck, and hang in there. The first 2-3 months are always a bit tougher.