Although it is registered only for human use, veterinarians can legally prescribe it for use with kennel cough, a common upper respiratory condition. (cuteness.com)
It is used for all sorts of conditions including rhinitis (inflammation of the nasal cavities), pharyngitis (inflammation of the tissues associated with the throat, vocal tissues, and oral areas associated with the respiratory tract), sinusitis (inflammation of the sinuses), conjunctivitis (inflammation of the delicate tissues around the eyes - which are often affected with upper respiratory conditions), and bronchitis! (animaleo.info)
Some find that the feathers aggravate upper respiratory conditions like seasonal allergies and asthma. (sleepmetro.com)