Hi we just adopted a female boxer about a month ago from the local shelter. She is about 6 months. Last week we brought her to meet a family members female golden retriever of about the same age. We introduced them slowly, but by the end of the night they were playing great together. No aggression even though they're both female. But a couple days ago we brought her back and tied them up next to each other and within a few minutes my boxer had the golden pinned down. Someone was able to quickly grab her so that was as far as it got. Is this a deal breaker? There were other people around as it was a small family get together. Maybe too much stimulation at once??