This is the final installment of a blog series on neurological diseases in horses. Most of the posts have been about Equine Protozoal Myeloencephalitis, or EPM. To summarize one of the main points of the previous four blogs, EPM is actually much rarer than most people believe. In fact, there are several rare neurological conditions that affect horses, and EPM is just one of them.
Occasionally, a veterinarian diagnosing a horse with EPM will suggest supplementing the horse’s diet with Vitamin E. Why is that?
Vitamin E is available in abundant amounts to horses that are consuming lush pasture grass. Vitamin E is considered an essential daily nutrient. To put it another way, horses are unable to manufacture Vitamin E and require adequate levels in their diet.
What horses might require Vitamin E supplementation?
Many of our horses don’t have access to green pastures year ’round. In one study, alfalfa hay lost 73% of its Vitamin E after 12 weeks of storage. (Equus article) Pregnant and lactating mares, young growing horses, and performance horses may require Vitamin E supplementation.
In addition to the categories just mentioned, some horses with neurological disease may benefit from additional Vitamin E in their diet. Vitamin E is a treatment for Equine Motor Neuron Disease. EMND is a degenerative disorder thought to be related to a Vitamin E deficiency. Alternatively, Vitamin E supplementation has no impact on Equine Degenerative Myeloencephalopathy. EDM develops in young horses. Researchers believe EDM is inherited and results in an inability to absorb adequate amounts of Vitamin E in the diet.
In this blog series, I have focused on EPM. Interestingly enough, horses with an actual diagnosis of EPM often have Vitamin E supplementation included in their treatment plan. A diagnosis of EPM is supported by documenting low serum Vitamin E levels.
How do I know when to supplement?
With this in mind, how does a horse owner decide whether or not their horse needs supplementation? Supplements are expensive and add an additional hassle to feeding chores. Too much Vitamin E might cause toxicity, with bleeding issues being the primary concern for horses.
First, you must determine if, indeed, your horse is deficient. This requires a blood test. Pathogenes lab offers this test. It is important to collect and handle the sample correctly, as test results are affected by the mishandling of the sample.
Secondly, if you decide your horse needs supplementation, you need to determine what type of supplement to give. What disease are you treating? If your horse is clinically normal, what options do you have for raising his Vitamin E levels to the normal range? A veterinarian treating a clinically ill horse will need to raise Vitamin E levels quickly. This might involve Vitamin E injections over a period of time. Usually, cheaper oral supplements will do the trick. However, there are different types of supplements available. Additionally, horses have unique responses to supplementation. Therefore, it may be necessary to try different formulations to achieve the desired results.
Lastly, how do you know when to stop giving the supplement? Dr. Ellison at Pathogenes suggests testing levels 7 weeks after starting supplementation. After 7 more weeks, discontinue the supplement, wait a week, and restest. This is the protocol for testing horses that are clinically normal.
For visibly ill horses, Dr. Ellison recommends a higher level of supplementation. She admonishes that it is critical to have a baseline level before starting supplementation.
What is the bottom line?
The bottom line here is that we shouldn’t just be randomly throwing high levels of Vitamin E into our horse’s diet. Personally, I feed hay all winter. In the past, my horses have had pasture all summer. Sadly, my pasture has yet to really get going. Prior to me purchasing the land a few years ago, it was a bean field. I don’t feed a high carb grain; instead, I feed Purina Enrich Plus. Enrich is a vitamin/mineral supplement. It is considered a “ration balancing feed.” It contains Vitamin E, but not at therapeutic levels.
If you have a horse with a neurological condition, ask your vet about Vitamin E supplementation. Test your horse’s serum level first! By the same token, if you own a “stressed” horse who is clinically normal, consider testing him as well. Do not randomly start and/or discontinue supplementation without knowing what you are treating and why. Too much of a good thing is not a good thing!
Next week I am going to move away from neurological diseases. I am still struggling with Kadeen’s recurrent eye issues. Next week’s blog will be a more in-depth look at equine autoimmune keratitis.
On a personal note, much has happened in my life in the past month! I just returned from beautiful Kauai where I spent two weeks with my fiance Alan! Our wedding date is May 2nd. We will be selling my wonderful barndominium (with tremendous sadness!) and moving to Colorado for the summertime. Winters will find us in Arizona. In the fall, we hope to load all the critters into our Living Quarters trailer and hit the Midwest. We want to watch the leaves turn colors! We are blessed and happy.