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


Drowsy, Seems to Fall Asleep on Feet, Could Even Collapse


Relaxed, normal horses often rest quietly with their eyes closed. Due to horse's locking limb anatomy (the passive stay and reciprocal apparatus), they can do this with minimal muscular effort. But if this behavior is excessive, it is not normal.

"Falling asleep on the feet" is a relatively common sign in horses that are actually sleep deprived. Horses must lie down periodically to get deep sleep. If they cannot do this, they become sleep-deprived. Narcolepsy (a sleep disorder) with cataplexy (sudden muscular weakness) is less common (and tends to be overdiagnosed) and is typically seen in horses that are active in work when they collapse. Repeated bouts of collapse, especially where cataplexy occurs, may result in injury to the horse or handlers, so be very careful.

  • 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 this seems mild or occasional and the horse seems normal otherwise.
    • If the results of the Whole Horse Exam (WHE) suggest the horse is otherwise normal.

your role


What To Do

Assess your horse for lameness or stiffness. Assess their management regime, paying particular attention to the stable in which they are boarded at night. Might there be some reason the horse is not lying down? Is the horse in chronic pain? Are they particularly anxious? Do you notice other signs of a problem? Share your findings and concerns with your vet.

Your vet will benefit from being able to see the behavior demonstrated. If it possible, try to take a video. Horses are inclined not to show the behavior when the vet visits!

your vet's role

Your vet will assess the horse's general health and body systems. A careful evaluation of history, physical exam and neurologic exam, as well as a review of your management may give a clue to the cause. If sleep deprivation is suspected, your vet may search for underlying causes such as lameness, neurologic problems, or chronic pain - anything that prevents the horse from being able to lie down to sleep. Narcolepsy/cataplexy might be confirmed using a challenge test involving the administration of certain drugs.
Questions Your Vet Might Ask:
  • When did you first notice this?
  • Does your horse seem normal otherwise?
  • Does the horse seem normal between episodes?
  • How frequent are the episodes?
  • What is the horse's age, sex, breed and history?
  • Does the horse have any other health problems?
  • Have you noticed the horse lying down and sleeping?
  • Have you given the horse any medications?
  • How is your horse's attitude and appetite?
  • 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

Author: Doug Thal DVM Dipl. ABVP