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


Abnormal Movement or Twitching of Lips


Abnormal lip twitching and trembling can be related or unrelated to eating. Occasionally, a horse's lips will move in a strange or inappropriate way when they are eating or offered feed. This is a rare finding.

Flehmen or lip curl can be a sign of abdominal pain (colic), but can also simply occur when a horse tastes or smells a new feed or grain. It is common stallion behavior.

Foreign objects embedded in the mouth and dental issues can cause strange lip movements, as can the ingestion of certain toxic plants, notably Yellow Star Thistle and Russian Knapweed.

Certain infectious neurologic (brain) diseases can cause abnormal lip movements too.

  • Code Red

    Call Your Vet Immediately, Even Outside Business Hours
    • If the horse has no appetite and is obviously depressed.
    • If you are not sure if your horse needs to be seen immediately or not.
    • 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 behavior continues with no explanation.
You also might be observing
Very Common
Less Common
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your role


What To Do

Observe the behavior for a while, and try to determine when it is happening. Take note of whether or not the behavior is associated with eating.

Assess your horse's general health using the Whole Horse Exam (WHE). Assess their mouth (wear gloves), and look at the inside and outside of the lips and look in the nostrils. Offer feed and water and observe what happens next. Can the horse eat and drink normally?

Contact your vet with your findings and concerns.

What Not To Do

Do not assess an ill horse's mouth without wearing gloves.

your vet's role

In this case, your vet will likely want to visualize the behavior, then assess general health before focusing in on examination of the mouth.
Questions Your Vet Might Ask:
  • When did you first notice this?
  • Have you changed your horse's feed or management lately?
  • Is the horse eating, drinking and behaving normally otherwise?
  • Describe your hay and feed supply?
  • What are the results of the Whole Horse Exam (WHE)?
  • Is the horse kept on pasture?
  • In what geographical regions has the horse lived in the last several years?

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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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