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


Twisting or Gaping Mouth, With No Bit in Mouth


Horses experiencing discomfort of the teeth, tongue, mouth or throat may gape their mouth open or twist their jaw as they eat. In this movement, the lower jaw is moved to one side or the other, out of alignment with the upper jaw. In some cases, the tongue protrudes.

This behavior often accompanies slow or difficult eating, or dropping feed. Horses may also do this when they eat something that they do not like, or after being given a dose of oral medication. Some horses with neurologic or severe body-wide disease will also engage in this behavior. A horse that has a foreign body lodged in the mouth will also do this.

  • Code Red

    Call Your Vet Immediately, Even Outside Business Hours
    • If the horse seems particularly distressed by the problem.
    • If the horse seems to be having difficulty eating, in addition to showing this sign.
  • Code Yellow

    Contact Your Vet at Your Convenience for an Appointment
    • If this seems mild or occasional and the horse seems normal otherwise.
    • If you consider this a chronic and relatively mild problem that is not changing rapidly.
You also might be observing
Very Common
Less Common
more observations

your role


What To Do

Assess your horse's general health using the Whole Horse Exam (WHE), paying particular attention to their attitude and appetite. Assess their mouth (wear gloves) and look for any other abnormalities. Offer the horse some hay to test appetite and the ability to pick up, chew and swallow hay.

Share your findings and concerns with your vet.

your vet's role

Your vet may observe the behavior and assess the horse's general health before doing a careful oral and dental exam.
Questions Your Vet Might Ask:
  • When did you first notice this behavior?
  • When did you last think your horse seemed normal?
  • How old is the horse?
  • Do you notice any other problems?
  • How is the horse's attitude and appetite?
  • When did your horse last have a dental exam or dental work?
  • Have you introduced any new feeds recently?
  • Did you just give the horse an oral medication or wormer?
  • What are the results of the Whole Horse Exam (WHE)?

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
more diagnoses

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
more treatments

Author: Doug Thal DVM Dipl. ABVP