Diseases of the nasal septum (the “wall” between the nostrils) are uncommon. A traumatic injury to the bridge of the nose of a young horse can produce nasal septal deviation and thickening. Other less common diseases of the nasal septum include fungal infection and squamous cell carcinoma (a type of cancer). Thickening or deviation of the nasal septum causes low-pitched noisy breathing during exercise. Facial deformity may be observed. Your veterinarian may be able to detect septal abnormalities by physical examination or endoscopic examination. X-rays of the skull can provide evidence of septal deformity, deviation, and thickening. Microscopic examination of any nodules or lesions on the septum will identify tumors, amyloidosis, or fungal infections.

Surgical repair of the nasal septum is the only treatment option in most cases. The incisions heal in a few weeks, but horses should be rested for about 2 months before returning to normal activity. After surgery, most horses make breathing noise during work, although less than before surgery, and exercise tolerance is improved. Shortening of the upper jaw, poor alignment of the incisors, or nostril collapse can develop if the procedure is performed in immature horses, so the surgery should be delayed until the horse has reached maturity, if possible.

Last full review/revision July 2011 by Bonnie R. Rush, DVM, MS, DACVIM; Neil W. Dyer, DVM, MS, DACVP; Joe Hauptman, DVM, MS, DACVS; Ned F. Kuehn, DVM, MS, DACVIM; Stuart M. Taylor, PhD, BVMS, MRCVS, DECVP; Wendy E. Vaala, VMD, DACVIM; Maureen H. Milne, BVMS, MVM, DCHP, MRCVS