My mother is a doctor. This means that throughout my life, I’ve come to her with myriad self-diagnosed ailments. When I tell her that I Googled my symptoms, and the internet says I have this or that rare disorder, she tells me that it’s most likely just diet or stress instead.

“When you hear hoofbeats, don’t look for zebras,” she says.

It’s one of my favorite expressions. Medically speaking, it means that nine out of 10 times, the most obvious solution is the right solution. I try to apply this logic to the horses in my life as well: Don’t blow things out of proportion, and take the most logical path to a solution whenever possible. Since I tend to overcomplicate things, this approach keeps me grounded.

Author Sophie Coffey and her mare Azul are finally on the path forward after a rocky start to 2022. Photos Courtesy Of Sophie Coffey

So when Azul started to resist the canter at the end of January, I wrote a blog post about all of the logical steps we were taking as a team to get to the root of the problem. Once published, I read through it no closer to a solution. The Gastrogard protocol wasn’t working, and while some days were better than others, I increasingly felt like the problem was me—that there was some judgment that first Callie and now Azul was passing about my riding.

I scanned the Facebook comments, bracing myself for the well-meaning but ultimately incorrect advice and saw several people suggesting something I had never heard of before: PSSM (polysaccharide storage myopathy). At first, I rolled my eyes; it had “zebra” written all over it. But hey, I decided, I don’t know what I don’t know, and I certainly didn’t know anything about PSSM—surprising to me because I consider myself to be a knowledgeable horseperson.

I typed “PSSM horse” into Google and came back with a bunch of articles written by Stephanie Valberg, DVM, PhD, DACVIM, at Michigan State University. As I read, an internal bell began ringing. Main symptoms in warmbloods include general poor performance and exercise intolerance. Symptoms are worse after prolonged rest. Symptoms are worse with diets high in nonstructural carbohydrates (starches and sugars). Symptoms can get worse about 10-15 minutes into work. Symptoms can be triggered by stress. The condition is prevalent in warmbloods.

I did the math. Azul’s resistance first started after a week of all-night grass turnout. I gave her three days of rest after her first bad day, and she came back even worse after the time off. Come to think of it, she was always a little worse after time off. She also was worse on cold/brisk days or in stressful situations that would light most horses up. She sometimes got “stuck” after a ride and took a while to get back into the crossties from the ring. She had a general laziness and unwillingness to go forward that didn’t track with her good-natured personality or her behavior when she first came up from Florida, and it became worse right around the 10-15 minute mark—right around when I would ask for the canter in most rides.

The main downside to having a solid lead? These sorts of muscle issues are notoriously difficult to clinically diagnose. Save for an invasive muscle biopsy, there is no real way to definitively say, “Yes this horse has it,” and even muscle biopsies often bring back false positives or negatives. The upside though was huge: There was a tried and true protocol for dealing with it, which consisted of simple diet and exercise changes.

Figuring I had nothing to lose, I spoke with my vets and trainers, and started the process of swapping feeds (to KER Re-Leve, a feed specifically designed by Valberg for horses with PSSM and other muscle-related issues) and adding supplements (Vitamin E and Tri-Amino, a muscle supporter). I also purchased a grazing muzzle that makes her look like the saddest horse in the barn during turnout, but is preventing her from becoming a Thelwell pony. And as the final piece, I started to replace most of her days off with active recovery walkabouts around the property in her halter, since horses with these tendencies do best with some sort of work nearly everyday, even if it’s just walking for 20-25 minutes.

Azul sports her halter-bridle, which she wears for her recovery walkabouts around the property.

Then, I waited. I like to take 15 days minimum to swap feeds, so of course the first week showed little change in her behavior. The supplements also took at least a week to really kick in. I was starting to get discouraged that I had chased down another false lead, but then in a Monday lesson on the start of the second week of her new diet, she walked with a little more pep in her step. She was a little less difficult to get (and keep) going, and her canter transitions were a little less sticky.

Each subsequent ride from then on had some sort of breakthrough moment. I had to keep her from breaking into the canter before a trot jump. I had to whoa to a distance or else she took me past it. We had one lovely canter departure and simple change after another. She went away from the mounting block with a swinging, forward walk instead of plodding along. She flatted two days in a row in the indoor ring (gasp!) and seemed to enjoy herself (double gasp!). Another good lesson, another good flat, another good day with Azul. The relief after each ride increased until I finally felt confident enough to write this blog post.

In the horse industry, we of course hear nothing but hoofbeats. There are certain issues that are so common (saddle fit, ulcers, teeth, hind end pain, hormones, etc.) that anything outside the box feels like you’re justifying bad behavior. A muscle-related issue might not be the first thing a vet would consider, and when I took it to my trainers, they reacted with the polite (but supportive) skepticism deserving of a nearly impossible to diagnose condition that has symptoms as broad and vague as “general exercise intolerance.” But sometimes, you have to push ahead and look for the zebra, even when your inner horseman rolls her eyes at you.

Since her recent dietary changes, Azul has developed lovely bonus dapples.

Of course I still don’t know exactly what was and is happening with Azul—but I do know that she now feels fabulous and happy in her work, and that’s what’s most important.

Sophie Coffey grew up riding by the seat of her pants in Virginia hunt country, and she took a flying leap into the top levels of the sport through sheer will and luck after a cold call landed her a job at Hunterdon, Inc. She continued freelancing as a jack-of-all-trades through her 20s for some of the top names in the industry, getting the best education possible in horsemanship and larger life lessons. After leaving the sport to pursue a career in marketing, she returned in 2018 as an adult amateur, and is currently teaching her baby warmblood mare Azul the ropes. She resides in Richmond, Virginia, with her fully indoctrinated horsey husband and several kitties. Follow her adventures between posts on Instagram @coffeyinthesaddle.