Take steps to manage your horse's weight and behavior while he's cooped up.
You’re headed out to catch your pastured horse for a riding lesson when you notice that his hock is the size of a softball. Later, you hold your breath as the veterinarian examines the injury and cringe at the sound of those two dreaded words: stall rest. Continuous confinement of any horse for long periods poses many obstacles, especially where nutrition is concerned. Diet plays a critical role in a horse’s behavior and overall gastrointestinal health, and not implementing a proper feeding program for a horse on stall rest can be worse than the injury itself.
Cutting the Calories
Whether your patient is a racehorse or a weekend trail horse, stall rest means a serious reduction in his usual amount of activity—voluntary and otherwise. Depending on his level of work prior to the injury, you will need to reduce his total calorie intake to account for the decrease in activity. Here’s an example of a 1,100-pound horse’s daily caloric requirements:
There are two main calorie sources in a horse’s diet: carbohydrates and fats. Carbohydrates are further divided into two types: structural and nonstructural. Horses receive structural carbs from the fiber found in hay and pasture. The nonstructural carbs come mainly from cereal grains, such as oats, and include sugar and starch. Fats, such as vegetable oils, contain approximately 2.5 times the calories of carbohydrates and are made up of long chains of fatty acids. The horse needs all these calorie sources to produce adenosine triphosphate (ATP), the fuel that powers the body’s systems, including the muscular and thermoregulatory systems, during physical activity. So the question is, what calories should you cut from the diet first during stall rest? To answer this, let’s take a look at the anatomy of the horse’s digestive system.
The foregut is comprised of the stomach and small intestine. Enzymes in the stomach break down most of the fat and nonstructural carbohydrates, which the small intestine then absorbs. Stall rest restricts a horse’s ability to forage—the act of seeking out and consuming small meals throughout the day. And horses that aren’t able to partake in their daily grazing routine can be predisposed to gastric ulcers, says Anne Baskett, DVM, Dipl. ACVS, a surgeon with a special interest in sport horse medicine and lameness at Tryon Equine Hospital, in Columbus, North Carolina. Saliva, which is high in bicarbonate and only produced by the act of chewing food, helps to buffer the stomach’s acidic secretions. Therefore, longer time between meals increases the horse’s risk for gastric ulcer formation.
The hindgut includes the cecum, large colon, small colon, and rectum and is the main site of fiber digestion. Within the cecum and colon reside billions of microbes charged with breaking down fiber into volatile fatty acids the body can use for ATP production. These microbes do not cope well with rapid changes to their daily routine or environment, such as times without adequate fiber, and health issues such as colic can result. In addition, researchers have found evidence that reduced or restricted locomotion can decrease a horse’s gastrointestinal motility—the movement of food through the digestive tract.
“Decreased physical activity results in decreased gut motility, and this can predispose a horse to impaction colic,” says Baskett. The hindgut is also the predominant place for water absorption, so impaction colic can occur in horses accustomed to ingesting and obtaining a fair amount of their daily fluid requirements from grass. Hay has a much lower moisture content, significantly decreasing the amount of fluid available for the large colon to absorb. So although these horses might be drinking as much as they usually do from their water buckets, their fluid intake is still drastically lower than normal.
Less water and more baled forage also make it harder for the digesta to flow easily through the twisty-turny cecum and colon, and it can become impacted.
“Cecal impactions are more often seen in horses locked up for orthopedic problems and getting NSAIDS (non-steroidal anti-inflammatory drugs) for pain,” Baskett notes. “Ileal (the final section of the small intestine) impactions can occur in stalled horses eating coastal Bermuda hay, even in horses that are used to this hay.”
Adjusting the Diet
Managing a stall-bound horse’s diet means more than simply adjusting for his reduced caloric needs. You also need to consider the type, amount, and timing of his meals, along with behavioral tendencies. But where do you start?
Keep the fiber Fiber provides the horse with more than just calories. Although researchers have not defined an exact required fiber amount, they do know it’s an essential daily requirement for proper digestive function, particularly in the hindgut. Studies have shown that when horses are fed less than 1% of their body weight per day in fiber, they are more prone to develop unwanted behavioral vices. Fiber, particularly in the form of long-stemmed hay, reduces boredom and stress and slows intake time. Therefore, make sure your horse is consuming, at the very minimum, 1% of his body weight in fiber per day.
Foraging behavior Grazing horses generally consume grass constantly during turnout, so it’s important to mimic this as closely as possible while on stall rest. Krishona Martinson, PhD, associate professor and equine Extension specialist at the University of Minnesota, suggests using a slow-feed haynet to extend foraging time. “Our research shows that horses consuming a hay meal from the stall floor take 3.4 hours compared to 6.5 hours when the same hay meal is fed from a slow-feed haynet,” she says. If a haynet is not available, feed hay in small meals at least three times per day.
Weight management For horses needing to gain or lose weight, stall rest presents an opportunity to pack on or shed a few pounds. You can achieve this by making simple, gradual changes to the horse’s diet and monitoring his body condition score (TheHorse.com/30154). Methods used to reduce weight include decreasing the nonstructural carbohydrate and fat portion of the diet while increasing forage intake. At the same time, ensure the diet is still meeting the horse’s other nutrient requirements (protein, vitamins, and minerals); simply reducing the amount of grain fed might not be ideal. Consider adding a ration balancer to reduce calories without compromising these nutrients.
Choosing the right calorie source is key to increasing weight without creating behavior vices. There is evidence that fat and fiber are more suitable calorie sources than nonstructural carbs, lowering spontaneous activity, cortisol, and subsequent stress levels. Look for feeds with highly digestible fiber sources (e.g., beet pulp, soy hulls), added fat, and low sugar and starch.
Weight gain takes time and patience, so it’s important to create a plan based on the duration of stall rest. The following table shows the additional calories necessary to raise a body condition score from four to five (on a nine-point scale) in a 1,100-pound horse. Pain, which reduces appetite, can delay this, so build in some extra time to achieve results.
Other Management Considerations
One of your most important goals when caring for any stalled horse is to manage his brain while his body heals. This is different for every horse and situation. Baskett recommends adding the following to your horse’s routine if on stall rest:
If the horse is able to walk, frequent hand or tack walks with plenty of grazing will help both the brain and the gut;
Changing the turnout routine of some of the other horses in the barn so the resting horse always has company goes a long way toward reducing his anxiety. Keep in mind that some horses tolerate stall rest better in a quiet, home environment, whereas others do best in busy barns with more stimulation;
The judicious use of sedatives, such as acepromazine, can also reduce anxiety in horses that are not tolerating stall rest. Avoid sedatives that decrease gastrointestinal motility, since we know stall-rested horses are already at an increased risk for impaction colic; and
If your horse is simply not tolerating his lockup, don’t go it alone! There is a growing number of rehab facilities across the country that specialize in caring for horses needing both short- and long-term stall rest. Many of these have underwater treadmills, swimming pools, and free walkers that are extremely helpful for a variety of injuries. Researchers have shown that such controlled exercise decreases musculoskeletal stiffness, promotes gastrointestinal motility, and improves attitude. The added benefit is that once your horse has healed, he’s likely to be a lot fitter and able to get back to his job sooner. Some of these facilities are able to transition your horse back to turnout and even to tack walking and trotting.
Flies can be extremely irritating during warm months, especially for horses on stall rest. Stable flies feed on blood and carry pathogens capable of causing infection, so protect and cover any open wounds. The following are a few feeding tips to help keep these pests away:
Use a separate bucket for grain only, and remove it from the stall when mealtime’s over;
Use fly protectant, such as a top-dressed feed-through supplement. This passes through to the manure with minimal absorption in the digestive system. Fly larvae present in manure can’t mature into adults. Many manufacturers add garlic to their feed-through fly protectants as a natural pest control ingredient. However, there’s currently no published research to back this claim; and
Keep all feed stored and covered when not in use, and cover buckets if you portion feed out before feeding.
Managing horses on stall rest can be a daunting task that requires careful diet planning for gut health. Mimic the horse’s natural behavior by feeding small, frequent meals and using a slow-feed haynet. Feeding highly digestible fiber sources and, if necessary, fat for calorie sources will reduce the horse’s chance of developing behavioral vices and digestive upset.