How to stop my new rescue dog from bullying my existing dog?
I'm sorry to hear that you're having these problems! Aggression or fighting between dogs in the same household is a complex behavior issue that's very difficult to address without evaluating the dogs in person, because there are so many factors to consider - it's important to assess both dogs' personalities, how they interact with each other when they're not fighting, how severe the fights are when they happen, what seems to trigger the aggressive behavior, etc.
For this reason, I would strongly recommend getting in touch with a veterinary behaviorist or a good reward-based trainer who can work with you in person to help determine why the aggression is occurring and put together a detailed treatment plan to address the problem. In the meantime, I would recommend keeping the younger dog on-leash whenever he is around the older dog to prevent any bullying or harassment, or using a baby gate or other barrier to keep the dogs separated until you are able to get some hands-on guidance in how to help them.
Updated on September 23rd, 2025