Ok well, we have been having some issues lately where Trigger reacts to something one of the others, in such a way that hurts them. Today, Bryco and I were playing fetch with a bully stick and Trig thought he would join in...by trying to rip Bryco's head off and making blood gush from around/at/in? his eye...while I was flushing his eye out with eye drops and checking for normal activity/dilation with the eye, I hear the new puppy yelping and get down stairs in time to see he's nipped her pretty good simply because she had followed Bryco and me to the gate/was near him (she's usually in her pen when I can't supervise but I had run upstairs w/ B as I was a little freaked out by all the blood). On a regular basis he has been reacting in a way that has either hurt Bryco or Oakley or he is fighting with Laurel. I am just afraid someone is going to get seriously hurt...he does not at a all realize he is 10x stronger than the smaller 3, and you can tell suddenly he is not being OK with being at the bottom of the pack like he has been. I am not sure the appropriate way to approach it other than I am starting to think I can't trust him alone with the other dogs during the day because its just been one thing after another where he has hurt one of them. I adore him to death but lately I feel like all I am doing is correcting him. We have had him since he turned 8 weeks old and he is 1 year old this week. I just think he does not know how easy it is for him to really hurt the smaller ones, he is one of the strongest/most muscular chihuahuas that I have seen and I don't know what to do so no one gets hurt. For the most part he is a very sweet dog, but he has been pretty defiant lately, and I wonder if it's just the age.