When my wife and I bought our first home three years ago, I finally had to come through on my promise to my wife for a large breed dog. In addition to our other two, a female britney mix (Rio) and a male aussie mix (Taz), we got a female rot/malamute cross-breed (Sky). Rio and Taz accepted the pup very well. At the age of one, Sky challenged Rio for alpha and has ruled the threesome ever since. All three dogs still get along fine.
Two days a go we added our fourth (and last) dog to our pack. An eight week old lab/weim cross breed. Once again Rio and Tax were very cool about it, but are a bit old now to go romping with a pup. But much to my surprise Sky, three years old now, hates the little guy and is furius with us for bringing him home. She has become willful and avoids the pup completely. When the pup tries to play she growls when the pup comes near.
Sky has always been the playful sort and has been disappointed as the two older dogs aren't as interested as they used to be, especially since she's twice their size. We assumed that Sky would welcome the pup as a playmate for years to come. I know that Mals can be a very dominant breed being closer to the original wolf blood than most other breeds, but I'm still very confused by her behavior. We are taking steps to train her that being around the pup is a good thing and we are hopeful she responds. Can anyone with some behavioral insight offer an explanation?

