Feeding Laminitic Horses
by: Christy West, Digital Editor/Producer
May 01 2007, Article # 9658
May 01 2007, Article # 9658
We've all heard that pithy little diet saying: "A minute on the lips, a lifetime on the hips." But while we can lose that weight (really, we can...), a laminitic horse's feet might not heal if he eats the wrong things or in the wrong amounts. So for a laminitic horse, that saying would accurately become, "A minute on the lips, a lifetime on the feet."
What's the best diet for a laminitic horse? It depends. When considering diets for laminitic horses, equine nutritionists divide these horses into two distinct groups:
1. Horses that became laminitic due to a dietary or metabolic trigger, and
2. Those that got laminitis due to anything else (mechanical overload, retained placenta, endotoxemia, etc.).
The second group has it pretty easy; it's assumed that they aren't overly susceptible to dietary or metabolic triggers, so they have no special "laminitis diet" requirements (although there are a few considerations we'll discuss later). But for the first group, proper nutrition can go a long way toward keeping them healthier, sounder, and happier. Conversely, the wrong nutrition can send them into a downward spiral ending in euthanasia.
Knowing what caused a horse's laminitis is the first step toward knowing whether he needs a special diet, says Lori Warren, PhD (nutrition and exercise physiology), assistant professor of animal sciences at the University of Florida. In this article, Warren and Sarah Ralston, VMD, PhD, Dipl. ACVN, an equine nutritionist at Rutgers University in New Jersey, offer their advice on how to feed these sensitive horses to avoid triggering more episodes of laminitis.
"Not every horse out there has a problem with lush grass, fructans (a type of storage carbohydrate in grasses), starch, and sugar--the vast majority do not," says Warren. "But if you have a horse with that propensity or a metabolic disturbance, diet change (such as a change in the composition of grass with a change in season) can cause problems."
For such horses, she has the following recommendations: "The number one goal is to gain control over what's going into their mouths. Free-choice feeding (i.e., pasture) is the first thing to go because you just don't know how much they're eating. You should also eliminate starchy grains, especially if that was the trigger--you don't want to trigger laminitis again."
Avoiding the pasture trigger You can't completely control pasture quality to get a uniform feed. Fertilizer, water, temperature, sunlight, and even time of day affect the level of sugars (carbohydrates) in the grass, and too much carbohydrate is just what a sensitive horse can't take. But if you can't control pasture quality, you can control how much time your horse spends on it.
"Controlling pasture access might simply mean less turnout time," says Warren. "You might need to turn him out on a dry lot instead, or turn out for just a few hours instead of all day. I prefer reduced pasture turnout even over a grazing muzzle because over the years I have met a lot of horses that learned to eat through the muzzle well enough that they might as well not be wearing one."
Ralston adds, "Sugars accumulate in grasses later in the day, so if you turn these horses out on pasture, do it in the mornings. Do not turn them out after an overnight freeze or after a prolonged drought (both conditions cause accumulation of sugars in grasses). In these conditions, you start keeping them off grass more and more. Also avoid overgrazed pastures, because when they're overgrazed, grasses accumulate a lot of sugar. Plus, sugars are higher at the base of the stems, which is what horses eat when the tops are gone."
Avoiding the grain trigger "Avoid anything like sweet feeds, avoid high starch intakes--most of these horses are obese anyway," Ralston advises. "You don't need to feed them grain or concentrate. But most owners will not go with the idea of just offering hay, salt, and water because they feel like they have to offer them something at feeding time. If you have other horses that are fed regularly in plain view of your 'problem' horse, do what I do with my fat pony--feed a few hay cubes soaked in water (two or three timothy cubes). They fluff up in the water, and I feel like I'm giving her more, but those few hay cubes won't founder her."
Alternate calorie sources "If a laminitic horse is thin and needs more calories, feed beet pulp or a forage-based feed with edible oil added (not mineral oil)," says Ralston.
"They can handle more calories from fat and fiber, but not starch," says Warren. "But a horse that's overweight to begin with doesn't need those calories; he doesn't need grain, so he doesn't need beet pulp or oil either."
Don't forget the basics Ralston reminds us that all horses, including laminitic ones, need plenty of water and free access to salt. "Give them at least 10 gallons of water a day; never let their water bucket go dry," she recommends. "As for salt, if they eat a whole lot of salt out of boredom, just use a plain white salt block. If they don't eat so much, a mineral block is okay."
Starvation Isn't the Answer
By now, it might be logical to think these feed-sensitive horses should be on a strict diet from all feeds. But starvation isn't the answer--feeding the right feeds is.
"These horses need forage," states Ralston. "Especially with chronically obese, laminitic horses, if you starve them and feed very limited amounts for long periods, they start to mobilize more of their body fat. This is good, but they can overmobilize. Excessive mobilization of body fat causes hypertriglyceridemia--high levels of fat in the bloodstream. That has to be handled by the liver, and if it's overworked they can get actual liver damage called fatty liver syndrome. It has been documented a lot in fat cats and ponies, especially when they go off feed for a few days.
"The older, more mature grass hays are fine--the stuff that most people will send back to the dealer," she goes on. "Feed limited amounts (1.5-2.0% of their body weight), divided into three or four feedings per day. Try to avoid prolonged fasting in these guys; you can give them really low-quality hay, just something to chew on for most of the day, then give them quality hay maybe twice a day."
Vitamins, Protein, and Minerals
In general, Warren notes that supplementing vitamins and minerals is often needed if a horse is overweight and you're trying to control his intake. "When you seek out stemmy, more mature, low-calorie hay so they have to eat more to meet their needs, that hay might not be high enough in vitamins and minerals," she says. "In that case, pairing with a supplement is a good strategy.
"In an ideal world you would get the hay and pasture tested and work out the horse's needs from there," she goes on. "But in the real world most people don't buy hay in bulk and don't know the nutrient concentration of their pasture, so the nutrients that are missing are unknown."
Ralston notes that even with lower- quality hay, supplements are usually unnecessary in adult horses that are not in heavy work. If your hay analysis shows that your horse does need a supplement, she gives the following advice: "Go with one good supplement and find out the protein in the hay. If the hay is really low-quality, feed a supplement that contains some protein and a good balance of vitamins and minerals. You do want them to get adequate protein to heal the feet (at least 10% of the total diet or 1.5-2.0 total pounds of protein per day for an adult horse)."
As for specific vitamins and minerals, no vitamin or mineral has yet been proven to improve healing in laminitic feet, she says. "Knowing what goes into collagen formation and bonding, biotin and methionine won't hurt and might help, but you don't want to start throwing cups of methionine on the feed," she notes. "They're micronutrients and should be fed in micro amounts. Thirty milligrams of biotin is less than one-quarter of a teaspoon."
The Complete Feed Option
To completely control your horse's feed intake, you might turn to a complete feed--one that's designed to provide all the horse's nutrient needs without adding any hay or pasture. What could be easier and more controlled than dumping his entire ration out of a bag like you might feed a dog or cat? But this approach isn't perfect either.
"These are kind of a neat feed source because everything is in the bag, but the biggest drawback is the lack of chew time, because that's their sole source of nutrition," says Warren. "They work well for dogs and cats because they are not designed to eat all day (like a horse is). But with complete feeds, in two hours horses can eat all the nutrients they would eat in about nine hours of grazing, and if you add hay for chew time, you add another component to their diets."
"I'd rather see owners go with the forages as much as they can," says Ralston. "Complete pelleted feeds are meant to be fed in large amounts, so their nutrient concentration is lower. Don't feed them as a supplement by themselves. They are good in a boarding barn when other horses are getting feed twice a day; it's good to give them something to rattle around in the bucket because if they are getting nothing and everyone else is, it raises their stress levels.
"Total mixed ration cubes that are forage-based and formulated to be fed free-choice would be an option if they are available in your region," she adds. "We have had very good success with such a product with our weanling/yearling horses. We feed them free-choice and supplement only salt and water."
Feeding Horses with Other Causes of Laminitis
We've spent most of this article on horses that are sensitive to carbohydrates, but we haven't forgotten those that aren't. These horses are not thought to need special diets, but Warren says that regardless of the cause of laminitis, the damage it causes in the feet is the same and warrants some vigilance.
"From that perspective, maybe we don't want to stress the animal any further by putting them in a situation that might result in carbohydrate overload," she comments. "I wouldn't be as restrictive as I would for a horse with a diet trigger, but I would certainly monitor the diet. It would also be good to know how much damage was done to the laminae--if there was more damage, I'd take more care with the diet.
"Over time, repetitive minor (carbohydrate overload laminitis) insults make it worse," she goes on. "And even in a horse that had road founder (from mechanical overload), if he had a lot of damage, a small carbohydrate overload could push him over the edge, while that would be only a minor issue in a horse with undamaged feet."
For this reason, Ralston notes that she would be very careful feeding grain to a previously foundered horse, even if he did not have a dietary trigger. If you need help designing a diet for your horse, Ralston suggests asking an equine nutritionist, preferably one that is certified through the American College of Veterinary Nutrition (www.acvn.org) or the Equine Science Society (www.enps.org).
Regardless of the cause of laminitis, exercising caution when feeding affected horses is the humane thing to do. Particularly for horses that are sensitive to high-carbohydrate and high-sugar diets, nutrition can either help them heal and become comfortable, or it can result in severe, chronic pain. Feed these horses a low-sugar, forage-based diet to give them their best shot at soundness.
- West, C. Cutting Down On Carbs (For Your Horse). November 2003, www.TheHorse.com/ViewArticle.aspx?ID=4777.
- West, C. Fall and Winter Bring Forage Risks. November 2004, www.TheHorse.com/ViewArticle.aspx?ID=1801.
- West, C. Nutritional Value of Forages. November 2004, www.TheHorse.com/ViewArticle.aspx?id=5249.
- West, C. Pasture Management Recommendations. August 2004, www.TheHorse.com/ViewArticle.aspx?ID=2356.
Put simply, a carbohydrate overdose changes the population of bacteria in the horse's hindgut, causing an explosion in the population of Streptococcus bovis bacteria. These bacteria produce toxins, which contribute to the damage of the intestinal lining and subsequently leak out into the bloodstream. From there, the toxins appear to either directly or indirectly stimulate increased production and activity of certain enzymes called matrix metalloproteinases (MMPs). The overactivity of these enzymes destroys the laminae--interlocking leaflike tissues holding the hoof onto the coffin bone. Now the horse has laminitis, which strikes with varying severity depending on the degree of the insult.
The concern with horses whose laminitis was triggered by diet is that those horses, for whatever reason, are more susceptible to that dietary trigger than other horses. Thus, their diets must be modified to avoid that trigger in the future.
Obese and/or insulin-resistant horses are also at greater risk of developing laminitis, although researchers don't yet understand the exact mechanisms for this. Managing these animals' diets to keep them at a healthier weight and avoid high levels of dietary carbohydrates helps reduce their risk of future laminitis episodes. --Christy West