We have an American Bulldog, Elvis, and a Chihuahua mutt, Frankie. Both are perfect with the chicks...they do like to play tag with the peeps, but I can't blame them for that one. I thought the dogs woud have the same reaction to the girls as they do with squirrels - barking, jumping, general freaking out - but I am SO happily surprised! And the chicks are beginning not to mind the dogs either. Zippy even pecks back at them!