Left: A standing CT scan of the rostral nasal passage with a normally sized nasal septum from a horse that did not present for a disorder of the nasal passage. Right: A standing CT scan of the rostral nasal passage at approximately the same location as the picture on the left, in a horse with an abnormal nasal septum. Note the marked thickening and enlargement of the nasal septum and the abnormally thickened alar cartilage (identified with a star). Also note the limited airway available due to the enlargement of structures within the nasal passage. This horse presented for respiratory dyspnea and noise. A diagnosis of fungal (conidiobolomycosis) infiltration of the nasal septum and alar cartilage was made and the horse underwent resection of the nasal septum and affected alar fold and cartilage.