Horse Side Vet Guide ®

Equine Health Resource

Sudden Collapse or Apparent Loss of Consciousness

Code Red - Call Your Vet Immediately, Even Outside Business Hours

Code Red - Call Your Vet Immediately, Even Outside Business Hours

    A horse suddenly falls to the ground, seemingly for no reason, as if they have fainted. This is a rare observation but can be caused by a variety of conditions, mostly affecting the heart or brain. This observation is also often confused with horses experiencing abdominal pain (colic). Rapid collapse in horses experiencing abdominal pain can look like a loss of consciousness, it can happen so fast.

    In some cases, horses will do this repeatedly and will seem normal between episodes. In that case, there are a few common diagnoses, including sleep deprivation and more rarely narcolepsy.

    Regardless of cause, this is obviously an emergency and you should call your vet immediately. If possible, you may perform a limited assessment of their general health while they are lying on the ground. But be very careful not to be injured. Stay away from the horse’s limbs and only work only from behind the back and neck.


    Only try to assess or treat the horse if you can do so safely. A down horse can roll very quickly and catch a handler, even if they are positioned correctly on the back side of the horse, so be very careful. When in doubt, wait until your vet arrives.

    Does the horse appear aware and alert? Gently touch around the eyes. Does the horse respond to your touch? Gently raise the lip to assess the color of the gums. What color are they? Gums of horses that are in shock from blood loss or other cause will usually be very pale. If possible, take pulse rate as well. Take note of whether there is involuntary limb movement (paddling). Promptly share your findings with your vet.

    Your vet may advise you to try to get the horse to rise. What happens then will provide value as to the cause of the collapse.


    While administering first aid care, your vet should fairly quickly get a general sense of the body system caused the the horse to be down. A specific diagnosis will often require a variety of other diagnostic tests and in some cases may not be possible. Horses that are down for hours from any cause have a poor prognosis.

    POSSIBLE TREATMENTS or TherapiesTo Lessen or Resolve the Sign

    Author: Doug Thal DVM Dipl. ABVP


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