I have had my chickens since they were a week old or so. The dogs have been around them most of the time. When they were still kept in the house, the dogs would be out when the chicks would have out door time. They are now about 7 months old and are free ranging in the back yard. The dogs don't mess with the chickens, however the rooster is picking on my female cocker spaniel. Since they free range, the chickens like to spend a lot of time on the deck (they sleep on the railing) so they are by the door in the morning and in the evening. The dog is terrified of the rooster. If he is on the deck she will not got outside (or if she is trying to come back in, she will stop dead at the bottom of the steps). He has gone after her some. I'm not sure what to do about the two of them. I don't think its fair for her since we have had her for so long.
