Nasal Discharge in Horses

Identifying Types of Nasal Discharge in Horses

(source The Naturally Healthy Horse)

Over the past years, I have come across more and more cases of snotty noses in horses. Sometimes it involves just one nostril other times it is both. So, here is some more information about the types and causes of nasal discharge in horses.

Nasal discharge in horses can come in varying colours and consistencies and can occur for different reasons.  Sometimes, it’s the result of something minor and will subside on its own, but in other instances, it’s related to something much more serious and will likely need treatment.

First off, here are some terms related to nasal discharge in horses:

  • Serous: clear and watery
  • Mucoid: yellow and mucous-like
  • Purulent: green-yellow, thick and pus-like
  • Sanguineous: bloody
  • Unilateral: occurring in one nostril
  • Bilateral: occurring in both nostrils

Some common and not-so-common causes of nasal discharge in horses as well as some identifying factors include:

  • Allergies:  bilateral, intermittent, serous to muco-serous discharge, may be accompanied by eye drainage;
  • Wind or Dust Irritation: bilateral, mild, intermittent, serous discharge;
  • Viral Respiratory Infection (Influenza, Equine Herpes, Rhinotracheitis and others):  usually bilateral, serous to muco-purulent, often accompanied by cough and possibly fever, can progress deeper into lungs and lead to secondary bacterial infection;
  • Bacterial Infections (Strangles, Pneumonia): usually bilateral, purulent, often accompanied by depression, fever, cough, enlarged lymph nodes, and other serious symptoms;
  • Heaves: bilateral, mucoid discharge, accompanied by cough and increased respiratory rate;
  • Sinus infection: unilateral purulent discharge, possibly foul-smelling, often occurs with tooth root infections, more common in older horses;
  • Infected nasal passage mass/ Sinus cysts:  unilateral possibly foul-smelling, purulent discharge, often causes facial deformity (swollen on one side of face)
  • Guttural Pouch Empyema (bacterial infection): unilateral or bilateral, possibly foul-smelling, purulent discharge, usually occurs several weeks or up to a few months after Strangles or upper respiratory infection;
  • Foreign body in sinuses: unilateral muco-purulent discharge, sometimes sanguineous discharge;
  • EIPH (Exercise Induced Pulmonary Haemorrhage): unilateral or bilateral, small amount of sanguineous discharge;
  • Ethmoid hematomas: intermittent, small amount of unilateral or bilateral sanguineous discharge, possibly accompanied by cough or breathing abnormalities during exercise.

Something to keep in mind is whether or not your horse has recently been to a show, trail ride, etc. where he/she may have come into contact with an infected horse.  If so, a viral infection may likely to be the cause of the discharge.  If your horse has fever or other symptoms with nasal discharge, don’t hesitate to call your vet.  Also, if discharge is sanguineous, obviously, the horse needs to be evaluated as well.

In less urgent cases you could consider using Homeopathy to support your horse during a snotty period. Feel free to contact me if you would like to know more about that.


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The information contained in this website is not intended to replace guidance from your veterinarian. Bowen Therapy and Homeopathy are complementary to veterinary treatment and the general care of the animal.