Cute dog, but I think he's more likely to hurt the chickens than they are to hurt him. I would just watch him/her and them and see what happens. Stay close so you can intervene if necessary.
I have a small dog (20lb miniature American Eskimo). She seemed to be fine with my hens, pretty much ignoring them. BUT, for some reason she killed one of my ladies last year. I don't know if she just didn't LIKE her or if she just had a bug up her booty that day, but no more unsupervised yard time for them!