Background: We have two basset hounds, one small female (now 4.5 years old) and one average sized male (now about 6 years old), who we rescued three years ago. They get along great, though the male has a tendency to show aggression to a small degree. We've curbed this situation by establishing dominance, and it has worked pretty well. The situation: We just rescued a male basset hound puppy, 4.5 months old, and we decided to keep him. Our female basset is in heaven, playing with the puppy around the clock. The male basset is at best tolerant of the puppy and at times is aggressive with him. The adult male will "correct" the puppy by lunging and snarly, and the puppy rolls over and whimpers. The adult has done no damage, and we break it up pretty quickly. What we've figured out is this: When I (the female owner) am not around, the adult male and the puppy get along pretty well, at least not fighting. When I am around, however, the adult male stays by my side and growls and snarls whenever the puppy comes near. The puppy has learned to be wary of the male and stays away, but sometimes he gets too close before he realizes it. I have realized that when we are on the couch and I am petting the adult male, he growls at my husband if he starts to pet him. Also, it is impossible to trim his nails, so we take him to a groomer, where he behaves just fine. At the vet, he won't let anyone touch him, so we have to muzzle him, but when they take him into the back by himself, he behaves perfectly. So, my theory is that I am the alpha female and he is protecting me, and/or he is challenging any other males from coming near me. Could I be on the right track with this theory? If so, what is the proper way to handle this? I have two conflicting ideas of how to correct this behavior, but I'm not sure if one of them would just reinforce the behavior. My first theory is that I should punish him when he behaves this way, and remove him from the situation. However, I worry that he will become resentful and the behavior will worsen. The second theory is to continue to show him affection and help him to understand that he is going to maintain his status with me, and he will adjust to the new puppy. However, I worry that this will reinforce his aggression and the situation will not get better. I would appreciate your thoughts on this situation and how I should handle it. Thank you.