Is Your Easy Keeper at Risk?

We call them air ferns. You know the ones. Instead of feeding hay in flakes, you feed in handfuls. And you measure grain in tuna cans instead of scoops. You limit their time on pasture, never give them treats, and buy them low-calorie hay. It’s just no fun at all. And no matter how hard you try, those horses still gain weight. And this isn’t just a cosmetic issue — easy keeper laminitis risk is very real. Eventually, you just give up. After all, your horse is happy. How much does it matter anyway if they’re a little fat?

I learned the answer to that question the hard way. I found myself looking into the eyes of my own beloved mare — 3 months pregnant — right before I euthanized her. She’d been living the good life out in the lush green pasture. I didn’t think much of it when she got a little foot sore. But then, it only took three days before she couldn’t walk at all. Her coffin bones had sunk down within her hoof walls — the most serious and life-threatening form of laminitis there is. Even after months of aggressive effort, she showed no signs of improving. It turns out that sometimes it matters a lot whether they get fat.

In this article, I’ll help you avoid the risk of experiencing a heartbreak like mine. First, I’ll explain why obesity is a real health risk for your horse. I’ll also cover how a condition called Equine Metabolic Syndrome (EMS) fits into the picture. Then, I’ll outline steps you can take to reduce those risks. Finally, if your horse is one of those air-fern types that gains weight no matter what you do, there are more options to explore. I’ll cover some additional strategies to discuss with your veterinarian.

Is He More Than Just an Easy Keeper?

Equine Metabolic Syndrome is the name given to a disorder associated with a horse’s inability to regulate glucose (sugar) in his bloodstream. When a normal horse eats a meal, his pancreas releases insulin. This hormone stimulates his body’s tissues to take up glucose and convert it into energy. Once the insulin has done its job, the pancreas takes a break and insulin levels in the blood return to baseline.

In horses with EMS, this cycle breaks down. The tissues fail to respond, so the pancreas releases more insulin into the bloodstream. The horse is then left with persistently high levels of circulating insulin. This breakdown, referred to as insulin dysregulation, is the fundamental abnormality that defines EMS. Abnormal fat deposits and obesity are the hallmark signs.

Just because your horse is an easy keeper, it doesn’t mean he has EMS. That said, his risk is high. And if he does get fat, there’s a possibility he could develop EMS as a result. It’s always fair to ask: “Is my horse fat because he has EMS? Or did he develop EMS because he got fat?” In fact, fat is an active metabolic tissue that releases hormones and inflammatory proteins. These can wreak havoc on your horse’s body, including causing the tissues to stop responding normally to insulin. When the tissues stop responding normally to insulin, glucose uptake is disrupted, and even more fat accumulates. So, the cycle begins.

The Laminitis Triple Threat

Beyond promoting the further accumulation of fat, persistently high circulating insulin can cause a host of other problems. Perhaps the most frightening is the increased risk for laminitis that can even be life-threatening. In fact, EMS and subsequent obesity are really a “triple threat” when it comes to laminitis. Fat also has significant hormonal and inflammatory effects. On top of that, the mechanical stress of extra weight can trigger a laminitis event. It’s easy to see why laminitis is the number one health risk faced by your overweight horse, but it’s not the only one.

As your horse gets fatter, he’ll face additional risks, including musculoskeletal injury due to the stress of excess weight on bones, joints, and soft-tissue structures. He’ll also have difficulties with thermoregulation that make it hard for him to cool down. As he grows older, excess fat can even raise his risk of developing a fatty tumor. This can lead to a severe colic episode.

What to Do About Easy Keeper Laminitis Risk

Whether your horse is simply fat or is suffering from EMS, effective management depends on three major things: controlling calories, limiting carbohydrate intake, and ensuring adequate exercise. But first, you must learn to recognize when he’s really fat.

If your horse is at a healthy weight, you should be able to easily feel his ribs when you run your flat hand firmly along his side. If you see fat deposits on either side of his withers, behind his shoulder, along his ribs, or at the top of his tail, he’s too fat. An obvious “crusty neck” is another common sign. And if he develops an obvious crease along his back, he may be hitting the danger zone. You can monitor his body condition visually or consider using a weight tape regularly to ensure he stays fit rather than fat. If he does start getting fat, the following strategies can help.

Calorie Control

More hay/less grain: Most of your horse’s nutritional needs can be met with good-quality hay. If you’re concerned he may be lacking essential vitamins or minerals, consider including a ration balancer that provides essential nutrients without adding extra calories.

Control how much you feed: Even hay can make your horse fat if you feed it in excess. The average amount of forage a horse needs is between 1.5% and 2% of his body weight per day (that’s between 15 and 20 pounds for a 1,000-pound horse), but this number will vary with the type of hay you feed. And remember — the extra little snacks count too!

Consider a slow-feed option: If you are concerned that your horse needs more to do, provide hay in a slow feeder or slow-feed hay net. These devices will help slow him down and ensure he gets plenty of grazing time even when you restrict his feed quantities.

Limit time on pasture: If your housekeeping situation involves grass pastures, you may have to limit turnout time. Provide your horse with a dry-lot turnout where he is still free to move around but does not have access to grass. You can also consider outfitting him with a grazing muzzle that limits his ability to graze. While grazing muzzles don’t work for every horse, when they do, they can be an outstanding option.

Limiting Carbohydrates

Choose carefully: When it comes to carbohydrates, it’s not about how much, but what you feed. When possible, select hay that has been analyzed and is less than 10% NSC (non-structural carbohydrates). If you have to play the odds, Teff hay tends to be lower in carbohydrates than other types of grass. And contrary to popular belief, alfalfa hay can also be a low-carb choice. It’s higher in calories than many other options, though, which means it must be fed in lower quantities.

Consider soaking: Soaking hay for 30 to 60 minutes can reduce the carbohydrate load by up to 50%. But beware. If you soak for too long, you’ll leach out essential nutrients. If your schedule means you have to soak for longer than an hour before feeding, your vet will likely recommend a ration balancer to make up for this loss.

Turn out in the morning: If your horse does get turnout time on grass, make it during early morning hours. Carbohydrates are lowest during that time of day, before the grass has spent time in the sun.

Exercise to Reduce Laminitis Risk

Do what you can: If your horse is sound, maintaining him on a regular daily exercise program is one of your best defenses against obesity. Exercise also improves insulin sensitivity. Consider it an important preventative measure. Unfortunately, if your horse is already suffering from laminitis, exercise won’t be possible as it may cause further damage to the sensitive structures in his feet.

Provide space: If your horse is OK to move around but not in regular work, make sure he has enough space with decent footing where he can exercise on his own. You can even consider feeding him in multiple small piles distributed around a large paddock to encourage him to move around as he eats.

Why Not Ozempic?

You’ve carefully curated your horse’s diet and have him on a rigorous exercise program, but no matter how hard you try he just won’t lose weight. What about Ozempic? It works for people, why not horses?

Ozempic is a GLP-1 medication that mimics glucagon-like peptide, one of the hormones that regulate blood sugar. It has been shown to be quite effective at facilitating weight loss in humans. Although research indicates it improves insulin response and could be an effective weight-loss drug in horses, too, it also has side effects. These include slowing the digestive tract, which raises concerns about colic risk.

Safer Medication Alternatives

There are other, safer medications your veterinarian can prescribe to help manage your horse’s obesity, beginning with levothyroxine, or thyroid hormone. In years past, horses were treated with levothyroxine after being presumptively diagnosed with hypothyroidism. We now know that horses don’t experience true hypothyroidism, but levothyroxine can still be an effective and safe medication to help boost metabolism and facilitate weight loss on a short-term basis. If your horse is severely obese or has failed to respond to measures involving dietary control and exercise, your veterinarian is likely to recommend this medication for three to six months. A wean-down period follows.

Another medication that may be recommended is metformin, a drug that’s commonly prescribed to human diabetic patients. It helps regulate blood sugar through a combination of mechanisms. These include suppressing glucose release from the liver, improving insulin sensitivity in muscle and fat cells, and decreasing sugar absorption from the intestine. Unfortunately, metformin is poorly absorbed in the horse’s GI tract, limiting its usefulness for our equine patients. It’s a safe, but questionably effective, option.

Emerging Drug Options

New on the horizon are a class of drugs called sodium–glucose cotransporter 2 inhibitors, or SGLT2i. These medications help control blood sugar by encouraging excretion of glucose in the urine. Early research in horses with an SGLT2i called ertugliflozin is promising, although more is needed before its use becomes widespread. Even so, this medication could still be an option for a severely affected horse where other options have been unsuccessful.

If you own an easy keeper, it’s no secret how hard it can be. And if you discover he has EMS, it can be even harder. Don’t be discouraged or give up. Watching your horse suffer from an unrelenting case of laminitis or, worse yet, watching them lose their life, is a price no one wants to pay. There’s no doubt it’s worth the effort it takes to maintain your easy keeper at a healthy weight.

Diagnosing EMS in Your Easy Keeper

It’s not hard to tell that your horse is fat. It may be a little bit more difficult to determine whether he has EMS. Does it really matter? In some cases, yes. Managing obesity will be more difficult for horses with EMS, and the risk of laminitis is high. Because EMS is only managed, not cured, knowing whether your horse truly has this condition will help you understand that careful, long-term management is especially important.

Diagnosing EMS can be easy if it’s severe — your veterinarian will simply measure resting insulin levels. If his insulin levels are significantly elevated and your horse is obese, especially if he has obvious, visible fat deposits, the diagnosis is pretty clear.

Unfortunately, it isn’t always that simple. Insulin is a very volatile hormone, and levels in your horse’s bloodstream can increase with other factors, such as stress. Even something as simple as a trip in the horse trailer can cause a spike. It’s also a hormone that can be tricky to measure, meaning your vet will need to pay close attention to protocols outlined by individual laboratories. If a resting insulin value gives an unclear result, your vet may recommend a more complicated challenge test that evaluates how your horse’s body responds to an intake of glucose.

The most popular challenge test for EMS is the Oral Sugar Test. For this test, your horse’s insulin levels will be measured before and after he’s administered glucose, often in the form of Karo syrup. If he has EMS, his insulin will spike higher after the challenge than it would in a normal horse.