I was given a 9 month old GP that was playing with chickens to death. The puppy was unsupervised on a couple of acres covered with feathered "toys". What did they expect? Anyway, she is a little over a year now and is still very much a puppy. We live in town and she owns the back yard. We have 2 hens that stay in the coop and just got 6 chicks. I have taken her in the coop and she is scared and wants out. I don't know if she would kill the chickens if I let them out and really don't want to find out. If I have to keep them separate, then so be it. I don't know what to say to you about yours, she is smart enough to do it when you aren't looking. You might have to keep the dog and chickens apart. The temptation may be too much.