I have a 2 year old Min Pin who loves me and my two young grandchildren. He does not like my grown sons and lunges toward my son when he comes home or leaves his room. He did not start doing this until we had had him for several weeks. He was 4 months old when we got him. Rusty was lost for ten days and after the eighth day, I got a new puppy as my grandchildren were heartbroken. He is a Shitzu, Pappillon, Chihuahua mix and is now 5-1/2 months old. Rusty does not like him either and I have never left them alone together. I have a 14 year old female Chihuahua and Rusty has no problem with her. I am reading the Alpha dog part of the book, but any other suggestions about how we can get Rusty to accept the others would be greatly appreciated. (I had a trainer come to my house about 8 months ago, and was shocked at the way he treated Rusty - he was basically holding him up in the air by his leash/choking him, so I haven't tried anyone else.)
Is your puppy neutered? Is Rusty neutered? Any time you have 2 unaltered males together, its difficult. So I would have them both fixed as soon as possible. That may help a lot with the two dogs. As far as Rusty and your grown sons...I would be matter of fact and tell Rusty to "cut it out" and pull him back by the collar. Do this each and every time he starts barking at them. Tell them to never kick at him or threaten him. Rusty is probably scared of them and this is his way of "sticking up for himself". If Rusty stops barking when you tell him to stop, praise him...maybe give a treat. Have you tried to let your son give him a treat? Dogs are so much like small kids in that they want RULES and they want to know what our expectations are for them. That's part of being the "alpha" of the house---you want to be the leader so Rusty can feel comfortable.
