Heat, I totally agree with you on both these points. I do believe chickens can recognize one dog from another and react differently accordingly. I had an old dog when we got the chickens and he was completely trustworthy around them. Slightly afraid of them perhaps, and gave them a wide berth. In return, they pecked and scratched around him without paying him any mind. Then he died and we decided to get a new dog. Went to a rescue where we could get a trial period with a potential new dog to be sure it was suited to our family and home prior to committing to adopt. Brought the new dog home and took her out on leash to see how she would react to the chickens. To my surprise, upon seeing the dog, the chickens went into panic mode and started flapping and screeching and running all over the place. The same flock that never reacted to my old dog at all. (To her credit, the dog didn't react and has now been a member of our family for a year, and the chickens are now as relaxed around her as they were the old dog, but that is a whole 'nother story). So yeah, I totally believe that your chickens are fine with your dog and, understandably, NOT fine with your uncle's dog being around.My chickens are fine around dogs... but not the one who killed one of them and scared the living crap outta the rest (including the two she had in her mouth when Uncle caught her and began BEATING her). My dog comes into the coop with me and they go straight up to him. He will sniff them and they will peck him if he gets too close. But they don't run in fear like they did when the other dog came up to their home.
Uncle should have had the COMMON SENSE AND DECENCY to leave his dog at home instead of bringing her onto OUR property, to OUR chicken coop. Honestly... my dog has protection issues and I keep him in my yard away from Uncles business, home, and dog (because Nanuq does not like her to put it lightly...) to prevent any mishaps. I would only expect the same from a grown man. It's called responsibility.