Horse Health

The Deadly Deficiency

Those of us who are around horses long enough will eventually be forced to deal with the inevitability of sickness and injury. Accidents happen, horses colic, bones break. Sometimes, the only thing we can do is make the heartbreaking decision to end an animal’s suffering. This experience brings into sharp focus the beauty and fragility of life. Unfortunately, my family was forced to make such a decision, and as dedicated, lifelong horse owners, it was one of the most difficult experiences we have ever endured.

Our horse had a very severe neurologic condition called Neuroaxonal Dystrophy (NAD), also known as Equine Degenerative Myelopathy (EDM). It had progressed to the point where treatment and rehabilitation options were virtually nonexistent. NAD is often misdiagnosed or confused as Wobbles (Cervical Vertebral Myelopathy) by veterinarians and horse owners alike. According to the University of California Davis, NAD is the second most commonly diagnosed neurologic condition in horses.

In reality these diseases are quite different. Wobblers originates from developmental abnormalities or physical trauma in young horses, and osteoarthritis in older horses, resulting in compression of the spinal cord. NAD/EDM on the other hand is the result of bad genetic luck, accompanied by vitamin E deficiency. These two factors together cause massive nerve damage throughout the animal. The most obvious symptoms include lethargy, incoordination, tripping, and irregular muscle tone.

Unfortunately there is no cure for NAD/EDM, but some cases can be managed through a simple nutritional approach to ensure adequate vitamin E intake (unfortunately, once the disease is sufficiently progressed, nutritional intervention does not seem to cure affected animals). High quality pasture is your horse’s main source of vitamin E. That is, hours of access to large amounts of fresh pasture every day for most of the year. A few blades of grass here and there will simply not be enough. Don’t think that feeding premium dried hay and top notch grain precludes you from this issue; dried forages lose nearly all vitamin E content within a matter of a few months of storage, and most commercially produced grains do not contain enough of this nutrient to meet your horse’s requirement.

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A straightforward blood test can determine your horse’s vitamin E status. Supplements of varying prices and quality are available for purchase. Note that natural vitamin E (d-alpha tocopherol) is absorbed at a higher rate than its synthetic counterpart (dl-alpha tocopherol). Michigan State University explains that this difference in “relative biopotency” is due to differences in isomer structure. Also, be cautious of supplements including other nutrients (such as selenium) since they often do not contain very much vitamin E and could risk providing dangerously high levels of other vitamins or minerals. Consult a veterinarian or equine nutritionist for more information.

Even if your horse does not possess the genetic predisposition for NAD or EDM, vitamin E deficiency by itself is still a major concern. You might say, “But wait a minute, my horse feels and looks FINE!” That may be, but why leave it to chance? We ask the world of our animals; they cut cattle, gallop races, turn barrels, jump fences, and take us on trail rides that make everything in our world seem better. Not to mention carrying our precious children, parents, spouses, and loved ones.

Most of us know at least someone who has been badly injured when a horse tripped or fell. How many of those horses may have been physically impaired due to vitamin E deficiency? Of course, any animal or person can have a mishap, regardless of nutrition. However, are you really willing to take that risk?

Discovering my horse had a severe vitamin E deficiency turned my world upside down. I wondered how, in a time of modern science and revolutionary veterinary medicine, equine vitamin E deficiency could be widely unknown (or, should I say, unnoticed?). I was frustrated and, to be honest, a little angry, but eventually came to the realization that sometimes things happen to us for a reason. Perhaps by making more people aware of this nutritional deficiency/disease, I can help prevent others from experiencing the tragedy that befell my horse.

All content is for informational purposes only. Contact your local veterinarian if you have any questions regarding the health of your animals.


About the Author

Throughout her childhood at the family horse farm, Heather Malcolm found her passion for equine nutrition, behavior, and wellness. After graduating with a degree in Animal Science, she gained a job in the companion animal industry. When she’s not riding her horse, she enjoys reading the latest equine research and cuddling up for a nap with her favorite dog.