1 chicken does not get along with dog

[Niss]

A young br is constanty fighting with the dog. I do not get it--the dog is not agressive with any other bird. All the other chickens and ducks get along with or avoid the dog. I see this chicken posturing and picking arguments with our dog, and I dont get it.
Currently I call the dog off, but is that teaching the chicken it IS dominate? Which could be a bad idea for the chicken...