Nasopharyngeal cicatrix syndrome (NCS)

Veterinary advice should be sought before applying any treatment or vaccine.

Nasopharyngeal Cicatrix Syndrome (NCS)

Cicatrix Syndrome

Nasopharyngeal cicatrix syndrome (NCS) is an upper respiratory tract condition of horses in which the pharynx becomes inflamed and irritated. Over time, the inflammation can lead to scarring that narrows and constricts the airway, restricting air passage in affected horses. Some horses require surgery in order to breath.

NCS Clinical Signs

Clinical signs of NCS in horses are related to the respiratory system, such as coughing, nasal discharge, exercise intolerance, flared nostrils, respiratory noise, extended head and neck, and increased heart rate. Affected horses may have one or more of these signs and some have no apparent symptoms whatsoever.

NCS Causes

The cause of NCS in horses is unknown, however it is thought to be associated with exposure to an environmental irritant in horse pastures. Treatment is generally unrewarding, as none of the attempted therapies have proven to be of much success, other than removal of affected horses from contaminated pastures may help stop exposure to the irritant and reduce the development of scar formation to the pharynx.


Nasal discharge
Exercise intolerance
Respiratory noise
Flared nostrils
Increased heart rate
Extended head and neck


  • History
  • Clinical signs
  • Physical exam
  • Upper airway endoscopy- evidence of inflammation and scarring of structures in the horse's throat.



Management relatedRemove horse from affected pasture will help to stop exposure to the irritant
Throat sprays
Pythium vaccinations
SurgeryPermanent tracheostomy


Scientific Research

General Overviews

Risk Factors

  • Pasture turnout - Horses on full time pasture turnout are more likely to get NCS then horses which are spend part of the day in the pasture, and part of the day in a stall.
  • Increased age - Horses have an higher risk of developing NCS with increased age. Most horses' diagnosed with NCS are 6-21 years old.