My previous birds were free range.... note the word previous. When I got them I had a cocker spaniel and a pit bull. They both did really well. I kept them away the first few days, but once I started giving them some time outside, I would have the dogs out there as well. I was outside during these ventures because the chicks were so little at the time. The cocker spaniel didn't really seem to care, however the pit loved them. He followed them, tried to be protective of them, sniffed at them it was really cute. Once they grew some and I kicked them outside, the 3 birds free ranged and the dogs went outside to do there business.... never had any problems. I had gotten them in early spring 2009. November 2009, I adopted a walker hound- bad idea to have a hunting dog with free range chickens. At that point, my rooster was starting to turn into an @$$ and would attack the cocker spaniel (like jump on her and what not). For months the rooster would "dare" the walker hound to mess with him, she would chase but never caught him. Eventually we got some more babies and while they were still staying in the house, the walker got a hold of the rooster and then it was on. She killed a total of five. Two adult and 3 like 12ish week olds. I now only have the cocker spaniel and she has been sniffing at the chicks, I don't think that she will do anything. She is terrified of my ferrets and once a chicken is full grown its taller than she is. I can tell you that my cats (indoor) are terrified of chickens. They haven't really noticed the babies... because they have been in their carrier (the chicks) when they are in the house. But in the past we have brought our adults inside for snow storms since we didn't have a well insulated coop for them. We would have them in a dog crate. The cats would hear them and be all freaked out.