In young horses as the result of injury from the bridle or severe
_coryza_, a circumscribed swelling sometimes appears on the outer flap
of the nostril, at first firm, hot and tender, with a surrounding pasty
infiltration, then forming into a tense elastic ovoid mass, the size of
a pigeon’s or chicken’s egg. It may become chronic and remain for an
indefinite period comparatively insensible to touch and only slightly
interfering with the movements of the nostrils. As soon as the elastic
tension betrays the presence of pus it should be evacuated by a free
incision made from inside the nostrils and the wound plugged with
medicated tow and allowed to heal by granulation.