Cornell Equine Seminar Series - "Pre-purchase Headaches in the Sport Horse: Risky Bone Chips, Lumps, Conformation and More!" presented by Dr. John Pigott, recorded April 18, 2023 via Zoom.

This lecture discusses common abnormalities and questions that veterinarians, buyers and sellers face during pre-purchase examination of the sport horse. If there is a bone chip, is it ok to still buy the horse? What are the chances of a conformational abnormality turning into a problem in the future? This seminar will explore the concept of risk assessment during pre-purchase and how to make the most informed decision when questions arise.

Read more: Pre-purchase Headaches in the Sport Horse

By Juliet M. Getty, Ph.D.

Magnesium – you hear about it a lot these days, particularly when it comes to treating obese horses, especially those with the telltale sign of insulin resistance – stubborn fat deposits along the crest of the neck and back, and behind the shoulders. And since magnesium is also involved with maintaining normal neuromuscular activity, supplementing it can have a dramatic impact on calming behavior, easing sensitivity, and improving muscle function and endurance.

How much?

The insulin resistant animal responds well to large amounts of supplemental magnesium[i]. However, magnesium needs to be balanced with calcium because calcium competes with it for absorption; therefore the magnesium content should be at least half that of calcium. Forages grown in areas of acidic or clay soils are typically low in magnesium. Compound this with low bioavailability, and your equine friend may be getting just enough to prevent a deficiency but not quite enough to maintain normal hormonal and nervous system functioning.

To help with regional fat deposits, I recommend supplementing magnesium to bring it in line with calcium. A 2:1 ratio of Ca:Mg is appropriate and can be as high as 1:1.

Consider this example: Your hay contains .25% magnesium and .60% calcium. Twenty pounds provides:

• 22.7 grams of magnesium (20 lb X 454 g/lb X .0025), and
• 54.5 grams of calcium (20 lbs X 454 g/lb X .0060).

Assume that only 50% of the magnesium from your hay is absorbed; therefore, only 11.35 grams of magnesium is provided by this hay. Supplement additional magnesium to bring the Ca:Mg ratio to 2:1[ii]. So in this example, you should supplement an additional 16 grams of magnesium to bring the Ca:Mg ratio into balance.

Obviously it is best to test your hay before supplementing magnesium. If this is not feasible, offer your 1000 lb horse a more conservative amount -- say 10 grams per day. Continue supplementing until you see the fat pads start to diminish (can take several months); then reduce the amount of magnesium by half.

To help with behavior or muscular issues, experiment by adding 3 to 10 grams of magnesium to the diet. Results should be seen within a week; if not, magnesium is not the issue.

Inorganic sources and absorption

Magnesium found in forages and feedstuffs is not well absorbed – only 40 to 60 percent. This has a lot to do with competition from calcium. Consequently, inorganic sources such as magnesium oxide, citrate, and sulfate have a higher absorption rate (70%) than magnesium found in natural sources.[iii] Comparisons between three inorganic sources are shown below:

Commonly Supplemented Inorganic Magnesium Sources and Concentrations
Source	Percent Magnesium	Amount needed to provide 5 g Mg[iv]	Comments
Magnesium oxide	56.2%	8.9 grams	Readily absorbed and most concentrated.
Magnesium citrate	11.0%	45.5 grams	Most easily absorbed but low concentration, necessitating larger amounts.
Magnesium sulfate	9.8%	51.0 grams	Epsom salt. Poorly absorbed and has a high laxative effect.

Whole foods

The magnesium found in natural sources is chelated (bound) to another molecule, such as an amino acid, to facilitate absorption. While the absorption rate is slightly diminished by calcium, whole foods boost your horse’s overall diet by adding additional minerals, as well as vitamins, fats, and protein.

Whole food sources of magnesium are not nearly as concentrated as a magnesium supplement. But they can aid in reducing insulin resistance, as well as protect your horse’s nervous system and muscles. These foods are especially high in magnesium, and are listed from high to low levels (found in one cup):

• Pumpkin seeds (shelled): 1200 mg
• Flax or Chia seeds: 660 mg (high in omega 3s)
• Sesame seeds: 500 mg
• Almonds: 400 mg
• Quinoa: 340 mg (high in starch)
• Wheat germ: 275 mg (high in omega 6s)
• Split peas: 230 mg

Can you give a horse too much magnesium?

Not likely. According to the National Research Council[v], the maximum tolerable concentration is 0.8 percent. Twenty pounds of hay testing at this level would provide a whopping 72.64 grams (72,640 mg) of magnesium. The gastrointestinal tract only absorbs what the body needs and the rest is excreted in the manure. However, since the kidneys are responsible for excreting magnesium, supplements should never be given to a horse with impaired kidney function; this would result in high blood magnesium levels, leading to neuromuscular symptoms such as depressed behavior and ataxia.

Bottom line

Many horses experience a borderline deficiency of magnesium because of its poor absorption rate from forages. Regional fat deposits, indicative of insulin resistance, can be reduced through magnesium supplementation (in combination with low starch/sugar diets and exercise), offering some protection against laminitis. Neuromuscular and behavioral sensitivities can also be alleviated with added magnesium.

This article originally appeared on Getty Equine Nutrition and is published here with permission.

Find more informative articles in our section on Health & Education.

Read more: Sources of Magnesium - Including Whole Foods

By SARAH WELK BAYNUM

The average horse owner may not believe that the Grayson-Jockey Club Research Foundation has anything to do with them. In actuality, there are countless horses whose lives have been saved as a direct result of the group’s research.

The Grayson-Jockey Club Research Foundation was founded in the 1940’s by a group of horsemen who originally donated their first equine research grant to the University of Pennsylvania. One of the projects that is currently being researched hits close to home for performance sporthorses—namely, spinal ataxia due to neurological diseases.

The group has funded research for a wide variety of breeds and disciplines—not just those in the Thoroughbred industry. Since 1940, the Grayson-Jockey Club has provided more than $42.3 million dollars in research money and underwritten over 437 projects across 48 universities.

This year, the Grayson-Jockey Club Research Foundation board of directors announced it will fund 11 new projects, along with 13 continuing projects, with an authorized expenditure of $2,455,164.

The Diagnosis Dilemma of Spinal Cord Diseases

Other than EPM, the definitive diagnoses for the underlying cause of spinal ataxia is extremely challenging.

Neurological diseases can often be career-ending diagnoses and causes for many horses. The two leading causes of spinal ataxia are cervical vertebral compressive myelopathy (CVCM, also known as Wobbler Syndrome), and neuroaxonal dystrophy / equine degenerative myeloencephalopathy (eNAD / EDM). These two diseases are the leading causes of spinal ataxia.

eNAD / EDM results from abnormalities of certain neurons in the spinal cord and brainstem. Horses are genetically predisposed to acquiring this disease. However, environmental triggers in the form of insufficient vitamin E are also required before you see clinical signs. 


Horses with eNAD / EDM have varying symptoms, ranging from mild performance issues to severe debilitation. Clinical signs commonly include incoordination, not knowing where their feet are, having an abnormal leg stance that’s too wide or too close together, difficulty with tight turns, going up hills etc. are all common.

CVCM on the other hand, is a developmental defect of the neck vertebrae that causes narrowing of the spaces in the spine. Malformation of the spine, osteochondrosis, repetitive micro-trauma, and dietary factors like copper deficiency, excessive zinc, or high carbohydrate rations can result in CVCM. Like eNAD / EDM, horses are unsteady on their feet with this disease and the symptoms can range in severity. Neck stiffness, inability to correctly place their feet, toe dragging, and decreased range of motion are also common symptoms.

Unfortunately, CVCM and eNAD / EDM are hard to differentiate because they have such similar clinical signs. The definitive diagnosis of these diseases is challenging while the horse is alive, and is typically made after the horse is euthanized.

This is because a there is no way to truly diagnose these illnesses—there are no MRI machines large enough to accommodate the size of a horse’s neck. The current way veterinarians are diagnosing CVCM is with x-rays and CT scans.

While Warmbloods and Quarter Horses are both breeds prone to these diseases, they tend to show clinical signs quite differently. For example, Quarter Horses with eNAD / EDM will have an associated vitamin E deficiency and begin slowly showing incoordination at a young age, while Warmbloods will have a more sudden onset of incoordination and behavioral changes between 5-15 years old without this vitamin E deficiency.

Because of how challenging it is to diagnose these spinal cord diseases, it creates a stressful financial burden and a career or even life-ending decision for horse owners and trainers.

However, thanks to the current research project being done by the Grayson-Jockey Club Research Foundation, a study is being conducted that includes a highly specific and sensitive blood and spinal fluid test that can be used in conjunction with the current standard diagnostic testing.

New Developments

It is expected this study will greatly improve the diagnoses of these spinal cord diseases overall.

“Currently, a definitive diagnosis for both eNAD/EDM and CVCM can only be obtained after a horse has been euthanized. Imaging such as CT/myelogram can assist with diagnosing CVCM, but we are in need of biomarkers that can be measured in the blood or spinal fluid of horses that could help us determine which of these diseases is the most likely,” says Dr. Carrie Finno.

The investigators of this project include Dr. Finno of the University of California-Davis, Dr. Amy Johnson of the University of Pennsylvania-New Bolton Center, and Dr. Steve Reed of Rood and Riddle, KY.

Through an innovative approach, 367 proteins involved in neurologic diseases in humans were screened and defined in the blood (serum) and cerebrospinal fluid (CSF) from confirmed cases of CVCM or eNAD / EDM in Warmbloods and Quarter Horses.

Based on the results of this screening, the researchers hope to validate these findings using bench-side antibody tests from the initial sample and a group of additional confirmed cases of equine spinal cord disease.

The hypothesis is that the concentrations of five specific proteins will help them distinguish between the two diseases.

The expectation is that the concentration of certain proteins in the serum will be higher in CVCM horses as compared to those in eNAD / EDM horses and those in healthy horses. Because Quarter Horses and Warmbloods present these spinal cord diseases so differently, it’s also expected the protein concentration will be higher in eNAD / EDM Quarter Horses versus Warmbloods.

Preventing Spinal Cord Diseases

For owners who plan to breed or purchase horses susceptible to these spinal cord diseases, there are a few preventative measures they can take to decrease the odds or catch it early.

“One of the most important things that owners can do is to have a thorough prepurchase evaluation performed that includes a detailed neurologic evaluation by an experienced veterinarian. When importing horses from Europe, this should be carefully considered prior to purchase,” says Dr. Finno.

“For eNAD/EDM prevention, supplementation with vitamin E early in life (i.e. the first year) can prevent the disease in genetically-susceptible individuals. Unfortunately, most horses are older than one year of age when purchased or evaluated and vitamin E supplementation after that time frame has been demonstrated to not be effective in preventing clinical signs of disease.”

Because of this, insurance might be something concerned horse owners should look into.

“The discussion about insurance is an important one to mention, since eNAD/EDM is not treatable and CVCM treatments currently have limited success in a moderate to severely uncoordinated horse,” says Dr. Finno. 

To learn more about the Grayson-Jockey Club Research Foundation, visit grayson-jockeyclub.org

This article originally appeared in the July 2024 issue of The Plaid Horse and is published here with permission.

There are more informative articles in our section on Health & Education.

The following is an excerpt from How Two Minds Meet: The Mental Dynamics of Dressage by Beth Baumert.

Horses are herd animals, and when it comes to riding horses, the importance of this fact is often overlooked and underestimated. All successful horse and rider partnerships are based on understanding the herd mentality.

By instinct, horses are “fight-or-flight” creatures, so they need a responsible leader to protect them in the face of threats. That’s how horses are in the wild, and those inclinations are still with horses that have been domesticated. They still need a leader and they will either fight or run away in the face of danger. Although your horse may come to trust you as his leader, it will serve you well to keep his innate needs in mind.

Emotionally, horses are as innately as different as people are, or as dogs are. Some are friendly, self-assured, and trusting like a Labrador; some are scrappy like a Jack Russell Terrier; others are insecure and unreasonably fearful. But unlike dogs who love you no matter what, horses require that you earn their affection.

When horses are wronged, they certainly don’t come back for more like dogs often do. They’re closer to cats on the spectrum of showing positive emotion. They might, in fact, feel love, but they don’t express it like dogs. Horses are matter of fact when it comes to what they like and what they don’t like. They’re more apt to show their fear than their positive responses. As a trainer working on gaining their trust, you try to reverse this trend. In the face of a fearful situation, a trained horse ideally turns to his rider for direction.

Being the leader isn’t always as simple as it sounds. Some horses wander aimlessly and don’t act as if they want to follow you. Others are pushy, and don’t appear to see you as the leader, either: they invade your space and don’t seem to want to be a follower. A horse might not be safe and trustworthy; you need to find a way for him to accept your leadership so you can trust him. Trust has to go both ways.

There are many different exercises and tasks that you can do to establish trust, like teaching your horse to respect your space, playing games together, being clear with your aids, and being trustworthy yourself.

The Limits of Leadership

When a new mare came into my daughter Jennifer Baumert’s life, she was eager to listen to everything the horse had to say. She wanted to get to know the new mare, so her first time in the saddle, she asked lots of questions: “How are you? How do you feel today? What’s your opinion of this and that?” The first day went well. Despite some basic connection issues, Jennifer felt she had a great rapport with the mare. The next day, Jennifer was armed with an agenda that she felt was a positive and appropriate plan. But the mare could feel Jennifer’s determination and felt threatened. In the past, other riders hadn’t been very kind and fair leaders, so the mare was immediately concerned about her rider’s position as leader. Jennifer was surprised that the mare suddenly became defensive.

Individual horses determine the limits to your leadership, especially when it comes to mares and ponies. There is a saying, “You ask a stallion, tell a gelding, negotiate with a mare, and pray with a pony.” Some might say you submit a 10-page request form to a mare! The bottom line is that all horses are different. When, over time, Jennifer’s mare grew to trust her, she was a very willing partner, but Jennifer always respected her leadership limitations—always made small talk during the warmup to check on the mare’s basic comforts.

Mares have a reputation for being opinionated because they have a keen sense of fairness. Ones with a history of less than ideal riding are particularly guarded. It isn’t simply about gender and temperament, but about history and whether the horse is trusting or not.

Fairness and Consistency are the Keys to Trust

To be seen as trustworthy, you need to be consistent, clear, kind, and fair. This doesn’t mean you spoil your horse. Consistency and clarity require the physical skill and ability to follow the horse precisely, then to give exactly the same aids for the same request every time. This helps the horse better understand what, exactly, you are asking. This is important in all aspects of horsemanship, whether you are working with your horse on the ground or under saddle.

How Two Minds Meet: The Mental Dynamics of Dressage
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This excerpt from How Two Minds Meet: The Mental Dynamics of Dressage is reprinted with permission from Trafalgar Square Books. Visit them online at Horse & Rider Books. All photos courtesy of Horse & Rider Books.

There a more really interesting books on riding and all aspects of equestrian living in our section on Books.

By Juliet M. Getty, Ph.D.

CBD’s popularity has mellowed over the years, but instead of fading into the background, researchers continue to expand and confirm its benefits. Most people think it is just one more supplement touted to relieve aggravating symptoms, but did you know that it is naturally occurring in our bodies as part of our endocannabinoid systems? Boosting levels that diminish due to age, stress, and illness can impact our body’s ability to heal itself.

I have written about CBD in an earlier article[i] where I explained how CBD can promote health for us as well as our horses. The goal of this article, however, is to expound upon the advantages of CBD and other cannabinoids and share with you what’s been recently discovered.

Review of the Endocannabinoid system

The endocannabinoid system (ECS) is a major signaling system that exists in you and your animals. It continually monitors any instability within the body and returns it to a state of balance or homeostasis so that the internal environment remains settled.

CBD (short for cannabidiol) and other cannabinoids are compounds that activate the receptors within this system. Cannabinoids, both naturally produced by the body (endogenous), and those supplemented from cannabis (exogenous), act as “keys” to these receptors, turning on a variety of health-promoting functions.

Within the ECS there are two main receptors -- CB1 and CB2:

• CB1 receptors exist mainly in the brain and central nervous system. They impact areas such as appetite regulation, memory, emotions, and feelings of pain.
• CB2 receptors are concentrated in the gastrointestinal tract and peripheral nervous system (nerve cells outside the brain and spinal cord) and modulate immune cell functions. When activated, they help reduce inflammation.

CBD does not make you “high”

CBD and THC (tetrahydrocannabinol) are the most studied, but they are only two, out of more than 80 different cannabinoids found in the cannabis plant. THC is intoxicating, and this is where many misunderstandings occur.

Hemp-derived CBD is not marijuana

Though both hemp and marijuana belong to the Cannabis genus, their genetic composition distinguishes them to produce vastly different amounts of THC. Hemp-derived CBD is high in CBD and very low in THC (less than 0.3%).

Hemp seed oil is not the same as CBD

It is important to understand that CBD only comes from the stalks, leaves and flowers of the hemp plant. The seeds, however, do not contain any CBD. Products just from the seeds such as hemp seed hearts, hemp seed pellets, hemp seed meal, hemp seed protein, or hemp seed oil, do not contain CBD. These hemp products offer quality nutrients and are highly beneficial for you and your animals.[ii]

If you want CBD, however, you should obtain a supplement[iii] that is third-party tested to ensure quality and consistency. You can download a CBD guide at CBDistillery’s website[iv].

How can CBD help you?

There are so many reasons to incorporate CBD and other cannabinoids into your routine. Here are a few conditions that are benefitted:

• Insomnia
• Anxiety
• Stress
• Post-traumatic stress disorder
• Pain and inflammation from injury
• Chronic pain[v]
• Cancer management[vi]
• Metabolic disorders

Understanding the CBD lingo[vii]

There are three types of CBD:

• Full-Spectrum CBD products. These contain naturally occurring cannabinoids such as CBN, CBG, and CBC, as well as terpenes and nutritious flavonoids. They do contain a tiny amount of THC, but it is quite small (less than 0.3%). All these compounds work together to provide a synergistic, “entourage” effect which multiplies their benefit. Full-spectrum CBD products are legal throughout the U.S. as long as the THC content does not exceed 0.3%. But each state has its own laws. The inclusion of a little THC enhances the efficacy in relieving symptoms.

• Broad-Spectrum CBD products. These start with full-spectrum extract and process it further to remove THC, resulting in a product with no THC (or no more than a trace -- less than 0.01%). Even so, they offer the entourage effect benefit because the terpenes and flavonoids are still present.

• CBD Isolate. This the purest form of CBD. Since it does not contain other cannabinoids, terpenes, or flavonoids, it is generally not as effective in alleviating symptoms. But it is a good choice in situations where testing is required (such as employment drug tests).

Read more: CBD and other Cannabinoids – How they can benefit you, your horses, and your pets

Foaling time is great fun on Flag Is Up Farms! The best way I know to accustom a foal to lead is with my Foal Handler. My lesson series on Equus Online Uni includes how to make this simple yet effective tool.

Read more: Foal Handling with Monty Roberts (2:00)

In this Stallside episode, we sit down with Dr. Daniel Devis to explore his approach to equine sport horse medicine, rehabilitation, and alternative therapies including acupuncture, regenerative medicine, and laser therapy. Dr. Devis shares practical insights into his methods, discussing how he blends traditional sport horse medicine with cutting-edge techniques to optimize recovery, well-being, and performance.

Read more: Rood & Riddle Stallside Podcast: Sport Horse Medicine & Innovative Therapies with Dr Daniel Devis

By Kentucky Equine Research Staff

Many people are familiar with melatonin as a sleep aid, but horse owners also may be aware of its role in mare cyclicity and reproduction. Few of us, however, know that melatonin, a neurotransmitter, may affect a horse’s temperament.

In the past, melatonin has been related to aggression in some species. For example, studies show that Syrian hamsters with high melatonin levels demonstrated more aggressive behavior than those with lower melatonin levels. One human study also found that participants administered melatonin exhibited more aggression in specific situations than those receiving a placebo.

To evaluate the effect of melatonin on temperament in horses, Korean researchers recruited 32 horses, all residing in a single riding facility in Korea for a minimum of five years.^* The horses were put through a series of tests by three different handlers to determine the following attributes and to assign a score from 0 to 5 with 0-1 being low, 2-3 medium, and 4-5 high:

• Docility—the time it takes to catch the horse in an unfamiliar situation;
• Affinity—the time it takes to become familiar with strangers;
• Dominance—the act of gaining the upper hand with other horses over feed; and
• Trainability—the time it takes to achieve a training goal.

The overall temperament was an average of the four scores, and those scores were compared to melatonin levels collected between 10:00 p.m. and 11:00 p.m.

No significant relationship between melatonin and any of the four temperament measures was identified, suggesting that melatonin cannot be used as a biomarker for horse temperament.

“However, melatonin levels were significantly lower in cold-blooded horses than in Thoroughbreds, which are considered hot-blooded. Those horses actively in a training program had higher melatonin levels than fully trained horses used for competition and riding lessons,” explained Catherine Whitehouse, M.S., a Kentucky Equine Research nutrition advisor.

Having a test available to potentially identify “safe” horses would be valuable to the equine industry, especially when purchasing horses for inexperienced riders or using horses as therapy partners. This could be used in combination with an evaluation from an experienced horse handler.

In addition to regular handling and training, diet and management strategies can help improve behavior-related issues in horses.

“Consider increasing turnout time with herdmates, maximizing forage availability, and supplying a concentrate feed that matches the horse’s energy needs. Some horses that tend to be hyperreactive may benefit from a feed higher in fiber and fat and lower in nonstructural carbohydrates when additional calories are needed beyond high-quality forage and a ration balancer,” advised Whitehouse.

Reprinted courtesy of Kentucky Equine Research. Kentucky Equine Research is an international equine nutrition, research, and consultation company serving horse owners and the feed industry. Our goals are to advance the industry's knowledge of equine nutrition and exercise physiology, apply that knowledge to produce healthier, more athletic horses, and support the nutritional care of all horses throughout their lives. Learn more at https://ker.com.

There a more informative articles in our section on Health & Education.

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