We just added a 4th dog a male chi, number 1 is a 2y f yorkie and 2 and 3 are 1 year old male Chi's. I too do not have the perfect dog home but it works for us. ( they are not all friendly to dogs and such) Each one of them have accepted number 4 differently .Number 3 was the worst he was not happy,he was afraid and growled everytime the puppy looked at him.We questioned our sanity several times. The last 3 weeks have been alot of work with the new puppy and watching over the pack but as each day passes the furbaby is growing and the dogs are bonding.Just do it slowly and show lots of praise to the others for being gentle and good boys.