Page 156 - January_2023

VETERINARY VIEWS
Poor performance may be related to sleep deprivation or to other diseases like endocrine disease.
Horses can experience sleep deprivation, often evident as excessive sleepiness during the daytime or collapsing episodes unrelated to narcolepsy or cataplexy (sudden loss of muscle tone while conscious or excessively sleepy). One tell-tale sign is the presence of chronic, recurrent abrasions over the front
of the fetlocks, and possibly the front knees
– these are indicative of episodic collapse from a standing position. Environmental stresses (noise, extreme temperature, unsafe environment, inadequate bedding), issues with herd dynamics, pain-related problems or late-stage pregnancy that precludes ease
of lying down, traveling and competition,
or hospitalization are various examples of situations that may deprive a horse of sleep. Video monitoring is helpful to assess a horse’s sleep behavior.
Hypersomnia is an excessive amount
of sleepiness, and an affected horse often performs poorly relative to its working history. Poor performance may be related to sleep deprivation or to other diseases like endocrine disease (like Cushing’s or pituitary pars
Narcolepsy is similarly characterized by excessive daytime sleepiness, but abnormal REM sleep is accompanied by cataplexy, hallucinations, or sleep paralysis. Cataplexy (sudden loss of muscle tone) is diagnostic
for narcolepsy, but a horse with narcolepsy
is not necessarily cataplectic. Usually, these episodes occur spontaneously but may also be triggered by intense positive emotions such
as those a horse experiences with grooming, stroking, feeding, turnout, or play. Familial relationships of narcolepsy have been identified in Miniature Horses but may occur in other breeds. Sleep deprivation is often confused with narcolepsy in the horse, yet narcolepsy is associated with a disorder of
a specific neuropeptide (hypocretin) that regulates sleep and wakefulness.
PROTECTION FROM FALLING
Sleep disorders in horses tend to occur during periods of inactivity in a stall, paddock, or in turn out. Some horses
fall asleep while being groomed yet catch themselves before they fall down. Horse
Familial relationships of narcolepsy have been identified in Miniature Horses but may occur in other breeds.
are reports of horses falling “asleep” while being led or even ridden.
A tell-tale sign of narcolepsy or sleep disorders is chronic abrasion of the front fetlocks and/or front knees. The falling horse catches himself by knuckling over
at the knees or fetlocks. Such sores can become chronic and fail to heal as the horse continuously traumatizes the skin. If such
a wound develops deep tissue bruising or infection, it has the potential to invade the joint and become a serious injury.
One means of protecting against traumatic fetlock wounds is by using neoprene boots,
intermedia dysfunction aka PPID), neurologic disease (encephalitis, West Nile virus, brain trauma, or equine protozoal myelitis - EPM).
owners need to remain cognizant of this fact to avoid getting hurt by a collapsing horse. Most horses do fine with exercise, but there
which the horse wears at all times when
not exercising. Alternatively, some form of bandage can be wrapped around the fetlocks
Late stage pregnancy
Some examples of situations that may deprive a horse of sleep are...
Extreme temperature Traveling
psy or sleep disorders is chronic abrasion fetlocks and/or front knees.
154 SPEEDHORSE January 2023
A tell-tale sign of narcole of the front