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Supplement Warnings From The Top

*If you compete, you are likely familiar with the USEF and FEI, but how familiar are you with their drugs and medications rules? Inside the pages of the FEI/USEF rules surrounding substance use are some scary truths that every single horse owner should understand about supplement use!

An Introduction to FEI Clean Sport & USEF Guidelines for Drugs & Medications

This weekend was supposed to be my first FEI 2*. Sadly, due to a crumbling last half of the season, this will not be, but my horse now has a passport and microchip! Isn't that crazy! According to a government website, less than half (42% in 2019) of American citizens have passports, yet by little Montana mare has one. As I was going through the multi-month process of registering my horse and working towards her passport, I came across the FEI Clean Sport initiative for both human and horse as well as the USEF Guidelines & Rules for Drugs and Medications. Being an equine nutritionist as well as a competitor, these documents caught my attention, because they reveal truths about the supplement industry that are difficult to share with horse owners. In order to explore this topic further, I reached out to the head DVM at USEF, every supplement company in my feed room, and read all 39 pages of the USEF guidelines. Here's what I learned...

  1. I need to be much more aware and cautious handling any sort of medication (consumable or topical) around my feed room including washing buckets and stir sticks after dispensing common NSAIDS.

  2. Intentional and unintentional contamination of supplements is real, but we are mostly unaware until a show horse tests positive. Supplement use in show horses comes down to blind trust in the company's manufacturing processes.

  3. Fines for violations are very expensive and could result in multi-year bans for competition.

The International Federation of Equestrian Sports or Federation Equestre Internationale (FEI), based out of Switzerland, is the governing body that structures and oversees horse sports all over the world including the Olympic Games. The United States Equestrian Federation is separate but related, overseeing the registration, rules, and policies of 11 breeds (i.e. Connemara, Paso Fino, Hackney), 10 national disciplines (i.e. English Pleasure, Western Dressage, Roadster), and 8 international events (i.e. vaulting, eventing, dressage) hosted in the United States. One of the primary purposes of these organizations is to ensure the fairness of competition, and they do that in part by maintaining an exhaustive list of banned and controlled practices and drugs/medications. They are governed by a panel of experts, science, and the welfare of the horse.

The USEF and FEI drug testing procedure is where, for many of us, the rubber really hits the road concerning feed and supplement safety, quality control, and company integrity. The FEI Clean Sport webpages and the USEF Guidelines clearly discuss the reality of supplement and medication use for the millions of sport horses in the United States. Like Dr. Schumacker states, “horse owners educate themselves only once their horse has a positive rating.” What he is referring to is the number of ways that horses could be ingesting controlled or banned substances without our awareness. [Definition of Controlled and Banned Substances is further down this article.] Sometimes those controlled or banned substances come from supplement products, because supplement companies do not test for them (unintentional contamination) or exclude them from their ingredients label (intentional contamination).

Despite 14 years in the feed and supplement industry including extensive education in safety and quality control protocols of manufacturing (i.e. HACCP, Safe Feed-Safe Food, USDA Organic, and GMPs), as a first time FEI competitor I was overwhelmed by the numerous ways in which my hay, feed and supplements could be contaminated and then test positive in my horse's blood or urine. I myself feed a joint supplement and a protein supplement along with my horse's regular feed and ration balancer. There are currently five feed and supplement products in my feed room along with two types of anti-inflammatories and more. I have chosen these products largely due to their efficacy and safety, but I also realized that this was an area that I needed to better educate myself.

Possible sources of contamination sitting around my feed room.

The WARNINGS You Need to Know

There are three documents within the collection of USEF and FEI guidelines that I’d like to point out. Implicit in these documents is an important truth about supplements that all horse owners should be aware of. The truth is, most supplements on the market today are unregulated by third parties which presents a significant risk for unwanted or unknown substances in our horse's diets- especially for horses showing under USEF or FEI oversite.

First off, and most striking, is the FEI Warning Regarding the Administration of Supplements to Horses. There is some very strong wording in this document that I rarely see in equine nutrition education today. The warning makes clear that horse owners, trainers and other responsible parties can NOT claim ignorance in the presence of positive testing. Whether the feed or supplement was accidentally contaminated, supplement ingredients were contaminated at their origin, or the supplement contained a banned substance not on the label (more prevalent than you might think with supplements), the owner, trainer and handler/rider is responsible. What this means is that said owner, trainer and handler/rider must be a) informed about controlled and banned substances, b) be aware of how feeds and supplements are sourced, manufactured, and labeled, and most importantly c) have full TRUST and FAITH in the feed and supplement company ingredients. This is a heavy lift for most horse owners.

Many horse owners will read this, and due to cultural conditioning, be more suspicious of the feed bag rather than the supplement bucket. However, feed companies are far more likely to test for substances than any supplement company due to the 2008 USDA Farm Bill that makes livestock feed highly regulated. It is DUE to this testing, and not despite it, that leads to greater safety from feed products rather than completely unregulated supplements that don’t test at all! It is for this reason that I make recommendations from brands that are more heavily regulated and tested.

The second is a document supplied by FEI Clean Sport titled How to Minimize the Risk of Contamination. Now, I'm going to leave it up to the reader to explore this document thoroughly, but there are a couple interesting points that I'd like to discuss. First off, your horse can test positive to a controlled or banned substance due to unknown contamination of hay/feed/supplements through it's environment or mishandling of medications. Even naturally occurring compounds found in certain molds and weeds could lead a horse to test positive. Now, obviously these are not due to human negligence and the USEF assumes your innocent until proven otherwise, but it does make us more AWARE, doesn't it. Secondly, the FEI suggests that all feeds and supplements undergo Naturally Occurring Prohibited Substances (NOPS) testing. According to company representatives, not one of the three supplements in my feed room undergo NOPS testing, because no NOPS testing sites exist in the United States. This should not surprise us considering how little regulation is done on MOST of the supplements on your feed room shelves. Lastly, I'd like to point out #6 under Hay, Feed an Supplements section. It states that "some supplements contain more substances than the ingredients list and some have been linked to contamination." The FEI's recommendation- "If in any doubt, do not give it to your horse." The 2021 US Equestrian Olympic teams carried freezers full of hay, feed and supplement samples with them to Tokyo in order to refute any positive drug testing while at the games that may have been caused by unknown contamination!

The third, is the USEF Guidelines & Rules for Drugs and Medications. Within the first three pages is a section titled “Caution Against the Use of Herbal/Natural Products”. I will simply point out that products marketed as natural are often the biggest culprits when it comes to unwanted substances due to ingredient sourcing. How much do you really trust the manufacturer and marketer of your natural supplement or topical products? Is the tiny possibility of performance improvement worth the risk of contamination?

Banned and Controlled Substances Testing

According to the FEI and USEF, there are substances that should NEVER be found in the competitive or non-competitive horse and these are labelled as BANNED. Banned substances include classes of drugs such as amphetamines, barbiturates, and cannabinoids. There are substances that are commonly used for their therapeutic qualities, but should be used appropriately around competition labelled as CONTROLLED. Controlled substances include many NSAIDS, corticosteroids, and antihistamines. "The difference between these two categories is in the penalty," says Dr. Stephen Schumacker, the chief administrator for the USEF Drugs & Medications Department. "Penalties include a 2 year ban for Controlled substances found in a horse and a 4 year ban for Banned Substances." As I read through the list of Controlled and Banned Substances as well as the guidelines, several common drug names came up that I recognized which made me realize just how easily we could naively misuse them before a USEF or FEI recognized competition. Here are a few that I have used or clients have used recently...

Common Use of Substances for Therapeutic Use

1) Joint supplements and injectable therapies

2) Dexamethazone for hives

3) Sedatives like Dormosedan for clipping, shipping, training

4) NSAIDS such as Surpass, Equioxx, Bute, Banamine, Ketofen, and Arquel for inflammation

5. Pergolide for Cushings Horses

6. Methocarbomol for use in myopathies (i.e. PSSM)


There are several steps that every competitor should take in order to educate themselves on this topic. First, we should all be reading the pages of the FEI Clean Sport initiative for both horses and humans as well as the USEF Guidelines & Rules for Drugs and Medications. Secondly, horse owners should gather all their feed and supplements together, point at each one, and ask "how much do I trust the marketer and manufacturer to provide a safe and effective product?" Call them up! Ask their primary nutritionist (if they have one at all, a) what quality control standards are implemented for each batch of product?, b) what third part regulators oversee the manufacturing procedures of the product?, and c) what are the credentials of the supplement creator? You could also ask if the product is manufactured in a ruminant drug free facility. You could also ask if their product has ever tested positive for any of the controlled or banned substances. Finally, is that product really worth the time, cost, and possible risks inherent in feeding any unregulated product? I bet you'll find the answers to be a bit scary.

On Course Equine Nutrition is committed to unbiased education of horse owners about their hay, feeds and supplements. Please check out RATE MY HORSE SUPPLEMENT for more in depth information about specific products. Natalie has taken the time to ask the above questions of the feed and supplement manufacturers for you.


2. USEF Resources for Athletes: Supplement Series 1-5 by TrueSport (Alicia Kendig Glass) Is it Risky to Use Supplements?

3. Downloadable PDF from USEF

4. Downloadable PDF from FEI

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