Crazy Horse (or, The Devastating Effects of Magnesium Deficiency)

Six years ago I became the owner, through a wonderful twist of serendipity, of a beautiful paint horse named Sunny. She was actually named “Sonny” then, but of course that was a boy’s name, so the “o” became a “u” the day Sunny became mine.


According to the former owners, Sunny had always been problematic. A handful. One of those horses that never really settled. Had plenty of go, not so much whoa. You know the sort. “No problem”, I thought. “I’ve never met a forward horse I didn’t like”.

Well, it turns out she’s more than just a little forward. Over the next five and a half years, she struggled with the following symptoms:

* she was on “high alert” all. the. time

* very tense, extremely hard (and over-developed) muscles

* extreme sensitivity to sound and touch

* very painful heats

* becomes more tense as a ride goes on, instead of relaxing

* once unsettled, she cannot regain her composure, and a meltdown almost always ensues

* intermittent and unexplained lameness

* hard keeper

* zero tolerance for change (one of her worst meltdowns ever occurred the day I tried riding her in a rubber snaffle instead of her regular snaffle; another, the first day I rode her in a new bridle).

After trying everything from grain changes to barn changes to changes in exercise, tack and shoeing, trying more work, less work, more playtime, more downtime, and anything else I could think of, nothing had improved. In fact, she seemed to be getting worse. Worse to the point of being dangerous. Worse to the point that I didn’t even want to ride this horse whom I had loved since the very moment I had laid eyes on her. I was devastated.

Then one day, after researching until my eyes were blurry, I started to notice a trend in the results I was getting when I punched her symptoms into good old Google. The term “magnesium deficiency” kept popping up, with all of the usual testimonials that sounded too good to be true. But I was so desperate that I was willing to try it.

The Science Of It All:

I am neither a vet nor an equine nutritionist. I’ve just done an awful lot of research on the topic, and the gist of it is that there are actual scientific reasons for the particular set of behaviours that are demonstrated by horses deficient in magnesium. This particular passage (from really hit home for me:

Magnesium deficiency has varying effects on the horse population. Some horses do not suffer any signs while others are almost un-rideable due to their apparent wariness and hyperactivity. Adding magnesium to their diet may have a dramatic calming effect. To understand why magnesium affects the horse in a calming manner, it is important to know what is happening in your horse’s body on a cellular level when there is a magnesium shortfall.

Calcium and magnesium work closely with each other, calcium requiring magnesium for balance. Calcium is in charge of contracting the muscle and magnesium looks after the relaxation or release of the muscle much like a gas pedal and a clutch work together. When a muscle cell is triggered, the cell membrane opens, letting calcium in and raising the calcium level in the cell setting off a reaction and the muscle contracts. When the contraction is done, the magnesium inside the cell helps to push the calcium back out of the cell releasing the contraction. This happens very rapidly.When there is not enough magnesium in the cell, calcium can leak back in causing a stimulatory effect and the muscle cannot completely relax. This can put the body into a continually stressed state. Low magnesium makes nerve endings hypersensitive thus exacerbating pain and noise.

Of course, that passage does come from the website of a company trying to sell me a magnesium supplement. But Dr. Eleanor Kellon, DVM, isn’t trying to sell me anything, and here’s what she says (from

Magnesium plays an important role in the function of the nervous system, and an excess or deficiency of the mineral can affect the behavior of the horse. Dr. Eleanor Kellon V.M.D. has performed field trials using supplemental magnesium for horses who displayed nervous behavior. She reported that while results varied depending on the specific problem displayed by the horse, magnesium had a noticeable effect on horses with anxiety, spookiness, and overreaction to sound or touch. She also noted that “aggressive horses were less easily provoked” when fed supplemental magnesium. Magnesium is a safe supplement, carrying no long-term side effects for the horse. It does not ‘drug’ the horse or change its blood chemistry at all.

I urge you to do your own research. Personally, articles like these and others were enough to at least convince me that a magnesium supplement might be worth a try.

Sunny started taking her magnesium supplement on April 16, when my rides had become so awful that most days I was just doing in-hand work in the indoor arena, and only when no other horses were present.

By April 25, I was able to walk her in hand with other horses in the ring. On April 28 we had our first successful outdoor ride of the spring. On May 11, I rode her in a lesson in the outdoor ring and, despite horses hacking by, a truck and trailer trundling up the road, and a rather close encounter of the pheasant-in-the-bushes kind, she was well-behaved almost to the point of placid, and we managed, for the first time in months, to get some real work done.

She has gotten consistently better since then. Her super-tense muscles have started to relax, and she is able to track up (at least at the walk) for the first time in… well… ever. She can handle previously unsettling situations with barely the blink of an eye, and she has come to love being groomed and fussed over like nobody’s business.

We’re by no means there. We have a long road ahead of us, and with her 21st birthday looming in just a couple of weeks, time is unfortunately not on our side. But we’re getting a little better every day, and that’s all I can ask of this wonderful horse who has probably spent the better part of her life fighting her inner demons.

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