When I first found Muttly, Travis hated him. He acted like he wanted to kill him while Muttly was in his kennel. So I took them outside to introduce them. I was worried Travis was going to hurt him, but once outside he liked him ok. I did this several time with both my older dogs ( never at the same time however) over a period of about a week. Then I let Muttly loose in the house first with Travis because I though he was the alpha dog. Meanwhile I kept Wilma outside. Then after that went well, I put Travis in another room and let Wilma inspect him. I also did this over several days. Then I let them all outside together, they got on fine, with the exception of the older dogs putting him in his place once in a while.

But then again Muttly is a puppy, I dont know if thats how you introduce adult dogs. But I thought I would share

Hope they get along!!