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


Swelling on One Side of Head or Face


Swellings on the side of the head or face can be caused by a variety of disease processes. Firm bony swellings on the side of the face are often presumed to be caused by dental disease until proven otherwise.

Traumatic swellings of the face due to trauma are common because of the horse's power, speed, and strong flight response.

  • Code Red

    Call Your Vet Immediately, Even Outside Business Hours
    • If the swelling is large, painful or growing rapidly.
    • 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.
    • If the horse seems to be having difficulty eating, in addition to showing this sign.
  • Code Orange

    Call Your Vet at Their First Available Office Hours
    • If you consider this a chronic and relatively mild problem that is not changing rapidly.
    • If the results of the Whole Horse Exam (WHE) suggest the horse is otherwise normal.
You also might be observing
Very Common
Less Common
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your role


What To Do

Assess your horse's general health using the Whole Horse Exam (WHE). Gently assess the swollen area noting its size, firmness, existence of heat, pain response, and whether there is any drainage. Consider whether there is nasal discharge or you note any smell. If your horse shows any other signs of illness or abnormalities, or if the swelling has not subsided in 24 hours, contact your vet with your findings and concerns.

What Not To Do

Do not ever attempt to lance, open or drain any swelling unless advised to do so by your vet.

your vet's role

Your vet considers the nearby anatomic structures that might be involved in the swelling. They assess general health with a physical exam, and may assess the mouth, looking for teeth that might be involved in whatever process is causing the swelling. Other diagnostics like x-ray (radiology) and less commonly, ultrasound may be needed to reach a diagnosis.
Questions Your Vet Might Ask:
  • When did you first notice this?
  • Do you see a wound?
  • Does pressure on the area seem to cause the horse pain or discomfort?
  • Can you send me a photo?
  • What are the results of the Whole Horse Exam (WHE)?
  • Is there any nasal discharge and if so, what is it's appearance?
  • Do you notice any other signs of disease, like coughing or lameness or respiratory noise?

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
Less Common
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Treatments Your Vet May Recommend

A way to resolve the condition or diagnosis. Resolving the underlying cause or treating the signs of disease (symptomatic treatment)

Very Common
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Author: Doug Thal DVM Dipl. ABVP