I have an almost five year old rat terrier and we recently decided to adopt another puppy both for me and my boyfriend and so my dog, Kiba, could have some companionship as well. The new puppy we named Anubis and he is a corgi/collie mix and about 5.5 months old. We actually had brought my dog to the shelter with us to meet the new addition and even though he wasn't excited to see the dog, he also didn't mind Anubis either (my dog isn't really dog aggressive but I have seen some dogs that he just wouldn't take to). It's been about a month now and Kiba is a little better with the puppy's presence but he still doesn't seem to like him at all. Kiba snaps at Anubis whenever her tries to play with him or if he gets too close. I know some of the reason is the transition from being the only dog in the house who gets all the love and attention to having another dog around that competes for the attention. I do everything I can to soothe my dog and show Anubis who the top dog is; I feed Kiba first, give him treats first, show him love first. I know a month isn't really that long of a time but I thought he would be further adjusted to the situation than he is now. He never tries to hurt the puppy and occasionally (rarely though its happened a couple of times) he will play tug of war with him, but how long should I expect this arctic front of his to last and what can I do to help break the ice?