Emotional Support Animal with Roommates

[Graham F.]

I own a duplex in Utah, renting out to single roommates. One roommate is moving at the new year and is trying to sell/transfer her contract. One interested candidate has an emotional support dog. I have a no pets policy. I'm worried how the dog can affect the living quality of the other three roommates, who are good tenants. Does the existence of roommates factor into fair housing or does it make no difference?