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


Drooping Lip, Face or Muzzle


Some horses, especially older horses that are very relaxed, let their lower lip droop markedly. This is usually a normal finding. When these horses become more stimulated, the appearance changes. The key to this is that the appearance is symmetrical on left and right sides.

A normal appearing contour of the face requires functioning facial muscles. Normal tone of these muscles requires an intact and functioning brain stem, facial nerve, and facial muscles. If any of these are disrupted, the horse's facial expression changes on the damaged side. Chewing function is unrelated and is controlled by completely different nerves.

When viewing a horse from the front, you may notice that on one side, the lower lip or muzzle droops or sags more on one side than the other. In some cases, it may appear to be pulled to the left or right. Usually, this appearance is caused by paralysis of the facial nerve on a side. In most cases, there is still feeling. The skin sensation is usually not affected as it is supplied by a different nerve. Facial nerve dysfunction usually results from traumatic facial nerve injury, but can result from a variety of other neurologic diseases.

  • 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 Yellow

    Contact Your Vet at Your Convenience for an Appointment
    • 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.

your role


What To Do

Assess your horse's general health using the Whole Horse Exam (WHE). Pay particular attention to general attitude, symmetry of the muzzle, and whether there is drooping of the eyelid on the same side as well. Contact your vet to discuss your questions and concerns.

your vet's role

Your vet will assess the horse's general health. If this is a one sided problem, your vet may conduct a neurologic assessment to try to localize the site of a neurologic injury and look for other neurologic deficits. Whether the droopy lip resolves depends upon the nature of the cause.
Questions Your Vet Might Ask:
  • What is the horse's age, sex, breed and history?
  • Can you send a photo of the problem?
  • Is the horse able to eat normally?
  • Do you notice other signs?
  • When did you first notice this problem?
  • Is the horse's attitude and appetite normal?
  • Do you recall an accident or injury in the horse's history?
  • What are the results of the Whole Horse Exam (WHE)?
  • Was the horse recently anesthetized?

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