Hello, My family recently rescued a dog who had been living in the streets for a while. He was at the vet for almost a week before we could take him home with us. At first, one of the times my father visited him at the veterinary, the dog (Koshei) bit my father. We have two other dogs who are also rescued, but they were still puppies, so we never had to deal with training an adult dog before. Koshei has no problems with my two other dogs, even though they are smaller Koshei has learned to leave them the space they need. However, the same is not true for the rest of my family. He sometimes keeps on growling to my father for no apparent reason. He has also growled to my mother and sister several times and attempted to bite them. The most recent occasion was today, when we found him resting on the couch, even though he isn’t allowed to be there. I was trying to get him to get down, but he kept growling and showing his teeth. I was scared to touch him because I know he does bite and leaves puncture wounds… We do not think that this is a good sign, we can’t socialize with him correctly because we are scarred of him lashing out and hurting someone. We haven’t been able to establish boundaries, when we try to Koshei turns aggressive. My father thinks we have to get harsher with him and impose physical punishment… My sister and I do not agree with this, because we believe he was abused before and he is now being aggressive out of fear. If this is the case and we impose physical punishment, would things just get worse? What is the best way to deal with the situation? Do you have any ideas of what could cause the aggression? I really don’t know what to do because I feel if we follow what my father suggests things will get worse for us and it would be a horrible thing to do to Koshei. I just don’t have any ideas or arguments to counter what my father is saying. Any help at all is greatly appreciated. (I’m sorry if there are any spelling or grammar mistakes, I’m not a native English speaker) Ps: both my other dogs usually growl at him if he gets so close it’s uncomfortable for them. Koshei usually whimpers a little bit and walks away. So, my father says that our two other dogs are doing something right because the new dog respects them but not us. So, the thinks we should follow the example of our dogs and “establish our dominance”.