What you see. The starting point for addressing any equine health related issue is your observation.


Discharge from Both Nostrils (White, Yellow or Green)


Mucous or excessive watery drainage from both nostrils is a very common sign of bacterial or viral upper respiratory tract infection. Upper respiratory infection is usually highly contagious, so your first consideration may be minimizing spread of disease to other horses. Wash your hands with antiseptic soap before touching other horses. Do not share tack or equipment with other horses, until your vet has seen the horse and determined the nature of the problem.

Two sided nasal discharge is also seen in respiratory diseases originating in the lower respiratory tract -windpipe (trachea) or lungs - as opposed to the sinuses and nasal passages in which there is usually discharge from only one nostril.

Small amounts of clear discharge from equine nostrils is considered a normal finding. White discharge is commonly associated with viral or allergic processes. Yellow discharge tends to be associated with bacterial infection. Green nasal discharge can indicate feed material within it.

A distressed horse with profuse green, watery discharge (containing feed material) from both nostrils and a deep cough likely has choke (esophageal feed obstruction). In very rare cases, intestinal obstruction can cause backup of fluid that ultimately comes out the nostrils.

  • Code Red

    Call Your Vet Immediately, Even Outside Business Hours
    • If this problem seems severe and has come on suddenly.
    • If the results of the Whole Horse Exam (WHE) in the resting horse indicate fever (Temp >101F/38.3C) or heart rate greater than 48 BPM.
  • Code Orange

    Call Your Vet at Their First Available Office Hours
    • If the signs are more intermittent and mild.
    • If the results of the Whole Horse Exam (WHE) suggest the horse is otherwise normal.
You also might be observing
Very Common
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your role


What To Do

Horses that have yellow or white nasal discharge may have a contagious disease, so use caution to prevent spread of infection. Assess your horse's general health using the Whole Horse Exam (WHE), paying particular attention to the presence of fever, whether there is a swelling or discharge under their jaw and throat, or feed material contained in the discharge. Share your findings and concerns with your vet.

your vet's role

Your vet's approach is to use physical examination and a variety of diagnostics to rule out infectious disease, choke and other common conditions. If there is risk of contagion, one of their priorities will be helping prevent spread of disease.
Questions Your Vet Might Ask:
  • Does the horse act depressed?
  • When did you first notice this?
  • How is your horse's attitude and appetite?
  • Has the horse (or any other horses in contact with this one) been exposed to other horses from off p
  • What is the horse's age, sex, breed and history?
  • Is there feed material in the discharge or drainage?
  • Do you notice problems with the other horses?
  • Do you notice swelling around the jaw or throat?
  • Have you noticed a cough?
  • What is the color and quantity of the discharge?

Diagnoses Your Vet May Consider

The cause of the problem. These are conditions or ailments that are the cause of the observations you make.

Very Common
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Author: Doug Thal DVM Dipl. ABVP