I just went through an RI infection with my adult male rescue, he was whistling when he breathed, at first I thought it was shed stuck in his nose and I did remove a large piece from his nose and the whistling stopped and returned the next day so off to the vet he went, I caught it on the onset so it wasn't advanced by any means and only required 4 injections to clear, this does not sound like an RI to me but a vet visit may give you peace of mind.