Obesity among equines seems to be a ubiquitous problem that leaves many owners seeking a weight loss program for their horse or pony. When it comes to devising a weight loss program, some caretakers turn to restricting the animal’s caloric intake; however, one research team found that it’s important to consider all possible materials that might be deemed as ‘food’ by a hungry horse, including stall bedding.

Wood shavings are a common form of stall bedding because they’re typically seen as inedible, but a team of researchers from the University of Liverpool School of Veterinary Science, in collaboration with scientists at WALTHAM, in the U.K., noted recently that horses placed under dietary restriction might turn to consuming these shavings.

“This was a finding that came to light from a larger study which was designed to investigate restricted nutritional protocols for the corrective management of obesity in horses,” explained Caroline McGregor-Argo, BVSc, BSc, PhD, Dipl. ECAR, MRCVS, an author on the study.

The researchers studied 12 mature, healthy horses or ponies with a body condition score (BCS) of 7 (out of a possible 9) or greater for 16 weeks. Animals were housed full-time in individual stalls with wood shavings with the exception of 30 minutes of turnout (with anti-grazing muzzles) each day.

Study horses were restricted to eating 1.25% of their bodyweight of a forage-based diet in order to achieve weight loss, but in measuring the ‘apparent digestibility’ of each horse’s diet, it became clear to the researchers that nearly half the horses were excreting a greater amount than they were being fed.

“The only biologically plausible explanation was that at least half of the animals were supplementing dietary provision from an alternative, ‘non-feed’ source,” the team said.

The team explained that the horse’s natural feeding behavior includes grazing for 40-60% of the day. When food intake and time spent eating is reduced, a horse might seek alternative sources of ‘food’ to fulfill this natural feeding behavior; in this case, the researchers determined that the alternative food source was the wood shavings the animals were bedded on.

Want to determine your horse’s weight? Learn how with our video tutorial and Horse Weight Calculator.

Although all animals remained healthy throughout the course of the study, “the potential is there for wood shavings to cause problems,” relayed McGregor-Argo .

The team recommends careful observation of horses on dietary restriction for weight loss, and “where wood shaving ingestion is recognized or indicated by fecal bulking, the use of rubber matting alone should be considered.”

The study, “Voluntary ingestion of wood shavings by obese horses under dietary restriction,” was published in the British Journal of Nutrition in October 2011. The abstract is available online.

In human medicine physical therapy (PT) is a well-established health care area. Likely because of physical therapists’ success in treating people, veterinarians and equine professionals have been using PT to help manage a variety of medical conditions, from bone and soft tissue injuries to weakness and inflexibility.

According to Jennifer Brooks, PT, Med, CERTP, owner and operator of Equine Rehabilitation Services LLP, in Brookline, N.H., some of these conditions include, specifically:

• Muscle injury/damage following trauma or surgery;
• Tendon injuries (acute and chronic);
• Osteoarthritis;
• Bucked shins, splints, curbs, and some fractures, such as otherwise “untreatable” pelvic fractures;
• Spinal dysfunction and back pain (described further in this article);
• Injuries or paralysis of the suprascapular nerve, which innervates (supplies nerves to) some of the shoulder muscles;
• Muscle atrophy (decrease in size/muscle wasting);
• Acute and chronic wounds (e.g., post-surgical healing sites);
• Neck, truck, and limb inflexibility;
• Stifle weakness and dysfunction (e.g., intermittent upward fixation of the patella);
• Recovery from neurologic disease such as equine protozoal myeloencephalitis (EPM) or equine motor neuron disease;
• Disuse contractures or atrophy during stall rest or immobilization; and even
• Loss of performance.

Although many enthusiastic owners, trainers, and veterinarians support using PT in horses, some members of the equine industry remain wary. The “science” behind PT in equine medicine is as inconsistent and unclear as it is with other complementary and alternative therapies, such as nutritional supplements and acupuncture (discussed in the August and October issues, respectively). For that reason PT has not been fully integrated into the care and husbandry of horses, despite the large number of medical and surgical conditions that equine physical therapists and rehabilitation professionals suggest are amenable to PT. Part of the problem associated with proving PT’s worth is this wide range of treatable conditions, the number of different therapy methods, a lack of research dollars to conduct studies, and the small number of horses in each study.

What is Physical Therapy?

Physical therapy refers to the use of one or more physical approaches to promote and maintain the body’s well-being, to help a horse recover from injury, and to re-educate an injured body part to move or function normally. Also referred to as rehabilitation, PT can include the use of various modalities such as heat and cold, hydrotherapy, therapeutic (not diagnostic) ultrasound, cold laser, and electrotherapy. First and foremost, however, a veterinarian should make an initial diagnosis of the problem before proceeding with any of these therapies.

According to veterinarians and other professionals to apply PT modalities:

Hydrotherapy involves applying water to an injured area to encourage healing. Cold hosing an injury to reduce inflammation is one of the simplest (and most beneficial) forms of hydrotherapy.

Cold therapy, similarly, helps reduce swelling in a recent injury and might be accomplished by pressing or wrapping ice packs around an affected area.

Heat therapy, on the other hand, causes blood vessels to dilate, increasing blood flow to the injured site to maximize healing. This therapy is used after pain and swelling/heat subside via cold hosing, hot compress, or a soaking boot (for lower limb injuries), among other approaches.

Therapeutic ultrasound involves using high-frequency sound waves to raise the temperature of selected deep tissues without heating the horse’s skin. Properly trained veterinarians and therapists might use ultrasound to treat musculoskeletal injuries and promote wound healing.

Laser therapy employs infrared wavelengths to stimulate normal cell activity that has been disrupted by injury. This method is most commonly used to treat injuries and joint pain and to repair wounds. As with other therapeutic modalities, laser therapy should only be administered by a skilled veterinarian or therapist.

Electrotherapy is the application of an electric current via surface electrodes to produce controlled movement of the skin, muscle, tendon, and associated ligaments. Sheila Schils, PhD (biomechanics/kinesiology), a private equine rehabilitator in Wisconsin, reviewed the use of electrotherapy devices in horses at the 2009 American Association of Equine Practitioners (AAEP) annual convention. She says there are two main types of electrotherapy devices: sensory nerve or motor nerve stimulators (see TheHorse.com/19048 for a detailed rundown of these devices).

Despite the widespread availability and use of rehabilitation modalities such as electrical stimulators, machines alone cannot replace a rehabilitation specialist’s own hands, skill sets, and problem-solving abilities. Schils says these devices can be an important part of the overall PT program, but professionals must use such equipment along with movement evaluations and exercises; this will improve the horse’s biomechanics and re-educate muscle memory, which will help heal the current injury as well as assist in preventing reinjury.

“Machine therapy on its own is far from satisfactory, and if it is possible to incorporate a rehabilitation program at the same time as the use of machines, the result will be far superior to the ‘machine only’ cases,” concurs Mary Bromiley, FCSP, SRP, RPT, a veterinary physiotherapist in England, in her 2000 AAEP convention abstract that reviewed these rehabilitation techniques.

Controlled physical activities, such as using a treadmill, underwater treadmill, and/or mechanical walker, schooling (in hand or under saddle), and swimming, for example, are also widely employed. These, along with manual techniques such as massage, stretching, and core stability training, are often employed in the successful rehabilitation of an injured or post-surgical horse, to assist performance horses during competition, and even aid mares during the postpartum period.

“Physical therapy should not be assumed to bring the horse back to pre-injury status, but should be viewed as a means to help heal the injury or surgery to the best possible outcome,” Schils adds. Further, once a condition has become chronic, it will be more time-consuming and challenging to return to the horse to his previous level of performance.

Does PT Work?

Currently, there is a notable lack of clinical trials assessing the efficacy or safety of machines and/or other techniques equine physical therapists use. Most of the information on PT is extrapolated from human medicine, and few researchers have conducted equine-specific clinical trials demonstrating PT’s efficacy.

In an attempt to provide a scientific ¬basis for using physical therapy and rehabilitation in the equine industry, Hilary Clayton, BVMs, PhD, Dipl. ACVSMR, MRCVS, the Mary Anne McPhail Dressage Chair in Equine Sports Medicine at Michigan State University’s College of Veterinary Medicine, has focused on conducting evidence-based studies that measure the effects of certain physiotherapeutic techniques in horses. Clayton, who is also vice president of the American College of Veterinary Sports Medicine and Rehabilitation, recruited Australian equine physical therapist Narelle Stubbs, BAppSc (Phty), MAnimST (Animal Physiotherapy), to join her research team. Their first study results were published recently in the Equine Veterinary Journal and the American Journal of Veterinary Research.

“Much of this research is based on proprioceptive (unconscious perception of movement or position of the body) stimulation and responses,” explains Clayton. “Stimulation of receptors in the skin results in activation of specific muscles that change the horse’s movement pattern. With practice, these changes can become permanent and persistent after the skin stimulation ceases.”

A key component of their research is to determine what type of skin stimulation produces the desired muscular response to overcome each horse’s movement deficit. For example, one approach is to use lightweight bracelets that brush gently against the skin of the pastern and coronet as the hoof moves.

Higher on the horse’s body, Clayton and colleagues are studying the effects of core training exercises on the horse’s neck and back. Clayton’s research has shown that performing baited stretches (“carrot stretches”) regularly over a three-month period can activate and strengthen the muscles that support and stabilize the horse’s back. These study results were published in the Equine Veterinary Journal in November 2010 and September 2011.

Kevin Haussler, DVM, DC, PhD, from the Orthopaedic Research Center at Colorado State University, is also making impressive headway in this field. Recently, Haussler and colleagues described their assessment of spinal manipulative therapy (chiropractic) and concluded that it can improve spinal flexibility in actively ridden horses.

Take-Home Message

Acupuncture has become more widely accepted as an alternative therapy for horses. Learn more about the history of this ancient Eastern medical technique and its application to horses in Understanding Equine Acupuncture.

The inclusion of rehabilitation discussions at some of the largest equine conferences in 2011 indicates that the discussion of PT is gaining importance. For example, Schils presented information on early mobilization, or controlled movement/exercise, for acute and chronic injuries at the Florida Association of Equine Practitioners conference, held in October. Based on her comprehensive review of the human and equine literature, Schils relayed that controlled early mobilization, within days of an injury or surgery, is beneficial and that immobilization is detrimental to the healing process.

These research studies and presentations show that physical therapy techniques appear to have potential in treating equine patients, just as they have come to be recognized as standard and effective modalities in human patients. But adoption of these modalities to the extent reached in human medicine “can only occur if the varied therapies are administered by a qualified person, correctly trained in the use of therapy apparatus, and who also possesses an in-depth knowledge of the physical demands of the individual equine disciplines,” says Bromiley. “Physical therapy should not be considered a ‘cure all.’ ”

For rehabilitation to be successful in horses, it “should not just rest on the shoulders of the specialist; it should involve the veterinarian, farrier, trainer, owner, barn manager, feed specialist, and saddle fitter, just to name a few,” says Schils. “The key is putting all of our heads together to come up with an excellent rehabilitation plan.”

Many equine caretakers have given or received these suggestions time and time again: “Just give him some Bute,” or “a little Banamine should do the trick.” While the use of these medications—both non-steroidal anti-inflammatory drugs, or NSAIDs—are indicated in some cases, it’s not uncommon for the substances to be overused. At the 2012 Western Veterinary Conference, held Feb. 19-23 in Las Vegas, Nev., one veterinarian discussed when NSAID use is indicated and what can go wrong if the drugs are overused.

As Elizabeth G. Davis, DVM, PhD, Dipl. ACVIM, associate professor and equine section head at the Kansas State University College of Veterinary Medicine, explained, NSAIDs have become “extremely commonplace” in the horse industry. This class of medication is known for its anti-inflammatory and analgesic properties, she said, and is often used clinically to “improve patient status and minimize pain.”

Some of the most popular systemic NSAIDs veterinarians and horse owners use are phenylbutazone (PZB or Bute), flunixin meglumine (Banamine), and firocoxib (Equioxx). Also gaining popularity is diclofenac sodium (Surpass), which is a topical NSAID. Other less commonly used but still effective NSAIDs are ketoprofen (Ketofen) and etodolac (Etogesic), Davis added.

Indicators for use include, but aren’t limited to, pain management for injuries or illnesses, pain management for chronic disease (such as osteoarthritis or laminitis); and fever control.

How Do They Work?

“The mechanism of action for NSAIDs is important to understand, particularly when we consider the use of several of these agents concurrently (also known as stacking) and recognize that many of the agents target the same enzyme system,” Davis explained.

Essentially, NSAIDs impair the inflammatory process by inhibiting the enzyme cyclooxygenase (COX). Cyclooxygenase converts arachidonic acid—derived from the membranes that surround cells—into molecules called prostaglandins. Prostaglandins participate in generating inflammation and fever. They are involved with the muscle soreness and stiffness that develop after an overstrenuous workout; the swelling and tissue deformation associated with injuries like bowed tendons; and fever in a horse with influenza. In horses with degenerative joint disease, prostaglandins contribute to the chronic inflammatory responses of joint effusion (fluid escape) and pain that result in a shortened stride or limp.

“What we’ve learned in the past two decades is that there are several forms of COX (1, 2, and 3) and some medications target one enzyme preferentially,” Davis explained.

The majority of commonly used NSAIDs are general COX inhibitors, while some newer NSAIDs specifically inhibit COX-2, she added. The most common COX-2 inhibitor on the market today is firocoxib.

What Can Go Wrong?

Even when NSAIDs are used appropriately, the drugs can still prove damaging to the patient, Davis said, and not all horses handle NSAIDs in the same manner. While many horses have no problems when an appropriate dose of medication is administered on a semi-regular to regular basis, other animals can develop complications even when they consume lesser amounts of the substances. It’s not clear why some horses handle medications so differently than others.

But researchers and veterinarians do know what kind of damage NSAIDs can inflict upon the horse. Davis explained that because NSAIDs compromise the body’s normal protective mechanisms, it leaves the horse at risk for developing a number of complications including:

• Toxicity;
• Colic;
• Protein loss;
• Diarrhea;
• Ulcers (gastric and oral);
• Right dorsal colitis; and
• Renal papillary necrosis.

Davis noted that dehydration, some preexisting conditions (such as ulcers), and high dose or chronic NSAID administration can increase the likelihood of developing complications.

Managing Complications

NSAID toxicity can have a guarded prognosis, Davis noted, so caution should always be used when administering drugs to horses. If toxicity is suspected veterinary consultation is essential. Therapeutic strategies typically include:

• Discontinuing NSAID use (despite the fact this might not seem like a problem, Davis noted that for horses that depend on low-dose NSAIDs to remain comfortable—like those with osteoarthritis or chronic laminitis—this step can be a challenge. In these cases, she recommends finding another means of pain control for the animal, such as a veterinarian-prescribed opioid drug.);
• Treating for concurrent gastric ulcers;
• Employing frequent, small volume feedings of a low-residue feed (such as roughage or complete pelleted feeds); and
• Monitoring hematologic values (such as protein levels).

With treatment, she explained, the horse’s attitude and appetite should improve, and blood work should show increased protein levels and normalized kidney values.

Stacking

If one NSAID works well, two should work even better, right? Wrong. Davis discussed numerous studies indicating that using more than one NSAID concurrently puts the horse at greater risk of developing complications or toxicity. Stick to administering one NSAID at a time, she suggested.

Understanding Equine Medications is your A-Z guide to learning more about generic and brand-name pharmaceuticals, possible side effects and precautions, and proper dosage.

Additionally, if administering two different NSAIDs concurrently is a bad idea, Davis stressed that administering an NSAID and a steroid at the same time is worse. Steroids like dexamethasone are much more potent than NSAIDs, she explained, and should not be used in conjunction with one another.

Take-Home Message

Even though a dose of Bute or Banamine might not seem like a big deal, NSAIDs should always be used with extreme caution. Work with a veterinarian to determine if a particular horse could be at risk of developing

A common approach to lameness in the equine athlete is non-steroidal anti-inflammatory medications (NSAIDs) treatments, such as phenylbutazone (PBZ, Bute) or flunixin meglumine (FM, Banamine) alone or sometimes in combination. At the 2011 American Association of Equine Practitioners convention, held Nov. 18-22 in San Antonio, Jonathan Foreman, DVM, MS, Dipl. ACVIM, of the University of Illinois, discussed the effect of these medications on lameness when used at a normal recommended dose with these strategies and whether combining the drugs confers any special effects.

Reversible lameness was induced in eight Thoroughbred horses by using an adjustable heart bar shoe that could be tightened with a screw to elicit severe non-weight-bearing lameness. After an hour of the shoe application, Foreman and his colleagues treated the horses with one or both drugs: PBZ at 4.4 mg/kg, FM at 1.1 mg/kg, or PBZ + FM at these same dosages. In line with findings from previous studies, the team found that peak effect of these drugs occurred four hours following administration.

The team measured heart rates as an indicator of pain since, as explained by Foreman, heart rate is a primary variable that is elevated in lame horses following exercise workouts. All NSAID treatments decreased heart rates for two to 10 hours after administration, while lameness scores decreased for 1.3-12 hours. Heart rate reduction indicative of pain relief lasted for 12 hours after giving FM alone and the combination of PBZ plus FM. Lameness scores decreased more quickly for PBZ or PBZ + FM combo-treated horses than for FM. Foreman concluded, “No significant differences were noted between giving PBZ alone or combining FM with PBZ.”

Understanding Equine Medications is your A-Z guide to learning more about generic and brand-name pharmaceuticals, possible side effects and precautions, and proper dosage.

Foreman reminded the veterinary audience that these drugs are not competition legal under FEI (Fédération Equestre Internationale) rules. As of Dec. 1, 2011, USEF (United States Equestrian Federation) rules allowed only one of seven USEF-approved NSAIDs, with combinations of NSAIDS no longer legal. “In an emergency such as a colic or eye injury,” reported Foreman, “additional use of FM can be given at a standard dose only by a licensed veterinarian.” Provided the approved paperwork is filed, the horse is allowed to compete no sooner than 24 hours later.

One of the biggest concerns he mentioned is the increased risk of gastrointestinal and renal toxicity as a result of administering PBZ and FM combination. He commented, “Recent work from another laboratory showed that combining half-dose oral PBZ with full-dose intravenous FM for only five days resulted in frequent ulcers and decreased plasma total proteins, indicative of gastrointestinal ulceration.” In this current study, Foreman showed that there is no benefit in effect from combining the two drugs, and he speculated that there is very likely to be increased toxicity if that combination is given over several days time.

Foreman stressed, “Giving twice the normal dose may not cause the analgesic effect to persist up to 24 hours, while this higher dose is toxic to kidneys and an already stressed gastrointestinal tract.” Since he found that combining NSAIDs achieved no better results than using either drug alone, Foreman stressed that there is no good reason to combine these NSAIDs.

A horse’s prolonged sweating during athletic activity or travel means a need for fluid and electrolyte replacement, and horse owners commonly turn to electrolyte products for this purpose. A team of equine researchers examined one electrolyte supplement’s (ES) effect on fluid replacement and performance, and Michael Lindinger, PhD, associate professor at the University of Guelph, presented the results at the 2011 American Association of Equine Practitioners convention, held Nov. 18-22 in San Antonio, Texas,

Dehydration significantly impacts the cardiovascular system, exercise performance, and recovery, as well as affecting thermoregulation (the horse’s ability to cool its body during exercise). Dehydration also affects mental acuity. Thus, effectively replacing fluids lost through sweating is of utmost importance in maintaining peak levels of health and performance. Lindinger pointed out that horse sweat contains significant concentrations of ions, such as sodium, potassium, chloride, calcium, and magnesium and these are sustained during exercise.

Keeping this information in mind, he and colleagues tested an oral electrolyte supplement specifically designed with proportions of electrolyte content to replace ion and fluid losses in sweat (“Most supplements have seemingly random proportions of electrolytes; when this one was developed it was the first to have ‘appropriate’ proportions,” Lindinger noted). Electrolytes marked with radioactive labels were administered through a nasogastric tube. In the first phase of the study, Lindinger examined how quickly electrolyte-supplemented resting horses cleared the supplement from the stomach (gastric emptying rate) by measuring disappearance of radioactivity from the abdominal regions using a gamma camera. Radioactivity from the electrolytes gradually diminished such that by the end of two hours, 82% of ES had emptied from the stomach.

The second phase of the study involved analyzing intestinal electrolyte absorption in horses at rest, and then exercising the horse to see if they performed better after receiving 3 litres of ES. They measured how fast sodium and potassium in the supplement appeared in blood plasma when the horses were resting. Lindinger reported that there was a more rapid uptake of potassium and sodium from the blood in ES-treated horses and that the electrolytes appeared in blood within 10 minutes of being orally administered, with sodium levels maintained during exercise and into the post-exercise period.

When investigators administered 3 liters of ES 60 minutes prior to exercise, those horses were able to exercise (at a moderate trot, about 6 mph) for 17 minutes longer than the control horses (treated with only 1 liter of plain water or 1 liter of ES), who became fatigued sooner. Providing more fluid volume to the ES-treated horses also seemed to enable better thermoregulation; these horses sweated more than the control horses. To support this, Lindinger explained that radioactive sodium given with the ES one hour before exercise appeared in sweat within the first 10 minutes of exercise and sodium levels were maintained throughout the exercise period.

He explained that dextrose in the ES enhances the small intestine’s uptake of water and sodium; while the dextrose elicits a glycemic response (glucose surges in the bloodstream), it is of a similar magnitude but shorter duration than what occurs with feeding. Most commercially available ES do not have dextrose, and this may impair test and slow absorption.

In summary, Lindinger noted, “An effective electrolyte supplement given prior to exercise serves to replace losses of ions and water and contributes to the ability of the supplemented horses to exercise for a longer duration.”

“This is the first ES supplement to be tested for effectiveness (functionality) in horses,” Lindinger concluded. “It is the first study to have measured gastric emptying of an ES in horses, and to measure electrolyte absorption in horses. It demonstrates that electrolyte supplementation provides water and electrolytes from the gastrointestinal tract to the rest of the body during the exercise period, and that this is helpful for improving performance (increased exercise duration).”

A horse’s digestion is closely tied to his overall health and well-being. Although people might be able to get away with a junk food-based diet for a while, a horse cannot, and food-associated diseases such as colic and founder will become an issue if a good diet is absent. And as seasons change, a horse’s nutritional needs require a little tweaking in order to avoid illness and weight loss. With a little forethought and common sense you can maintain that all-important digestive health throughout spring, summer, fall, and winter.

Spring

During the spring pasture quality tends to be different than in the late growing season or during winter. This younger grass typically is richer and more nutritious than later in the season.

While many owners feel that that gradually introducing their horses to lush spring pasture is important for digestive health and stability, Brian Nielsen, MS, PhD., PAS, Dipl. ACAN, professor of equine exercise physiology at Michigan State University, suggests owners consider another train of thought.

Spring pasture has a mix of both green and dormant plants,” he explained. “If you pull (the average horse) off this and put them back on when everything is green, they will just gorge themselves. If you keep them on the pasture and they start to search out the little green stuff, they will be acclimated to the changes.

“However, if you have insulin-resistant horses, gradual introduction might make sense,” he added. “New pasture growth high in fructans might cause some problems for them.”

So, according to Nielsen, while there is some risk of colic and founder when turning horses onto fully green pasture cold turkey, the odds are most horses will handle the transition well.

If your horse is completely new to pasture (such as a Thoroughbred that has just come off the track), most veterinarians recommend turning out for an hour each day and extending each day by an hour or so to help the horse adjust gradually. If you’re concerned about overeating, you might also consider putting a grazing muzzle on your horse.

Owners with good-quality pastures can count themselves lucky as the nutritional value of living forage is very high. But should you supplement with hay? Nielsen said you can, but you’ll likely notice that your hoses ignore the hay altogether when adequate grazing is available. (Note: For information on what pasture plants grows best in your area consult your local extension agent.)

Summer

Summer in the southern parts of the country–especially the more arid areas–can feel worlds away from the northern parts. William A. Schurg, PhD, PAS, Dipl. ACAN, professor of animal science at the University of Arizona (UA), suggested that one method to consider for keeping horses cool in hot summer climates is to feed them less forage–a practice carried out at UA.

“(In the summer) we feed more high-fat and soluble fiber diets,” he said. “Hay forages have a higher heat increment or heat of fermentation than more soluble starch-type feeds like grains or protein supplements. So in the summer months when the temperatures are reaching the 100ºF mark, we don’t want to create excess internal body heat so we reduce the amount of dry forage that a horse eats and replace it with fats, oils, or concentrates, such as the newer low-starch, high-fat and soluble fiber products that create less internal heat upon digestion. Therefore, the heat of fermentation is lower and the horse doesn’t have to struggle to rid his body of excess internal heat. Overall, he will be able to regulate his body temperature better.”

Schurg suggested eliminating several pounds of dry hay from the diet per day during the summer and replacing the calories with a low-starch feed or mixture of oils (usually an omega-3 fatty acid source) as a topical dressing.

In the cooler parts of the country, where pastures are more standard during the summer months, people are sometimes fooled into assuming the grass they see is full of nutrition, but Nielsen cautioned it’s easy to get tricked by all that tall grass.

“Tall mature grass is actually low in protein, energy, vitamins, and all the good stuff horses need (apart from fiber),” he explained. “The more mature the grass, the more stem it has and the less nutritious it is. Two thirds of nutrition in grass is in the leaves, so you want to have grass with a lot of leaves and less stem.”

The best way to keep your pasture “young” is to mow it several times during the growing season, which will also keep the invasive weeds down and make the grass more palatable. Conversely, if your horse gains weight easily, consider letting the grass grow taller, which can help keep weight manageable.

“The problem here is that the horses will chew some areas short and leave the tall stuff,” Nielsen cautioned. “The parasite load increases because the horses will hang out there, and overgrazed plants will have damaged root growth and be susceptible to dying off.”

Autumn

Fall is when horse owners in the south can breathe easier, but for their northern neighbors, fall means preparing for winter. For horses this could mean packing on some extra weight to prepare for winter’s higher energy requirements.

“Go in (to winter) a little on the chubby side by increasing the hay,” Nielsen advised. “It doesn’t hurt to add some corn or vegetable oil to the diet … if you do have a hard keeper, grain with fat added can be a good option.

“Sugar beet pulp is a nice fiber source high in soluble carbohydrates,” he continued. “It is easily fermentable fiber so you don’t have to worry so much about digestive problems. Incidentally, it’s a high-energy source that is low in phosphorus (unlike some grains), which is an extra benefit because the horse won’t have a high phosphorus excrement that’s released into the environment.”

Winter

Horse owners in northern climates know that on a bitter cold day, they can warm their hands by pushing them deep in their horses’ coats. The heat that keeps horses warm on even the most unbearable winter day is produced inside the digestive tract, which is fueled by fermentation. In other words, horses have their own little central heating system. You can help keep that warmth flowing by providing the right materials. For the horse, this means fiber.

“When a horse digests long-stem fiber (hay), microbial fermentation occurs and heat is created,” Nielsen explained. “This has a benefit to the horse in times of cold weather because fiber is digested slowly and heat is sustained for quite a long time.”

Although Nielsen said it’s difficult to pinpoint a precise amount to feed, an extra flake of hay on a cold day is generally a good idea. Other calories gained from fat and grains, such as corn, can still be used for warmth, although it won’t produce that long, sustained heat. A horse will use that feed for whatever purpose it needs, whether it is running a race or keeping warm, but fiber will always generate heat.

Year-Round Water Needs

Water is the most essential nutrient for the horse. Plenty of clean, fresh water should be available to the horse at all times, but horses will also change their drinking patterns season to season.

Schurg says in southern parts of the country during the hot summer months, a horse’s water intake increases from 4-8 gallons of water per day during 65ºF (18ºC) days to 20-40 gallons of water during 100ºF (38ºC) days. During extreme cool weather water intake might be compromised and the horse will drink significantly less than needed.

Feed intake is related to water intake, and it’s generally believed that a horse will take in about a 4-1 ratio of water to feed on average.

“Inadequate water intake has a direct effect of feed intake and maintenance of digestive health,” Schurg said. “Adequate water intake allows for a more uniform mixing of feed particles and aids in movement of digesta through the digestive tract and helps enzymes and bacterial to more effectively breakdown the digesta. Inadequate feedstuff breakdown increases risks of impaction and gaseous colics.”

Schurg said he prefers owners offer horses water via a bucket or barrel rather than in the small automatic waterers. Horses like to put their lips and face down into the water to get a drink, and the small bowl automatic waterers don’t allow the horse this option, he explained.

“Also, in our environment (in Tucson), we found that during the hot summer months horses that were in pens under roof began to have bouts of abdominal distress,” he added. “We found that horses were not drinking enough water because the small bowl waterers were heating up to more than 100ºF and burning the horses’ mouths. Ultimately, we placed barrel waterers in their pens and also soaked their hay prior to feeding to aid hydration.”

Nielsen also noted that horses on fresh, green summer pastures get their water intake from different sources than they do in the winter.

“For instance, in the summer when forage is green, horses may drink less because there is moisture in the grass,” he relayed. “In the winter all the moisture they need comes from the water tank.”

To help your horse keep his body temperature up in the winter, make sure that his digestive tract is able to function at peak performance. That means ensuring he has a readily available source of drinkable water, Nielsen said, adding that snow alone does not suffice as a water source for horses.

“A horse would not be taking in enough water if you rely on him eating snow,” he explained. “Also, a horse will use up a lot of calories getting that snow from the solid state to the liquid state, so it will be that much harder for your horse to keep his weight on.”

Learn more about the importance of nutrition, vaccinations, and deworming programs designed to keep your horse healthy in Understanding Equine Preventive Medicine.

More so, horses are much less likely to drink cold water than tepid water. Most water tank heaters keep the water a few degrees above freezing, and as long as there isn’t any ice floating in the water, the majority of horses will find this temperature satisfactory. But if you have worries about a particular horse getting enough water, warming his water up could encourage him to drink more.

Take-Home Message

No matter what the weather, always make sure that hay is free of mold and dust, grain (if fed) is given in small meals, and, of course, water is readily available. Having your horse dewormed regularly and teeth checked routinely also contributes to proper digestive function. Good horse keeping along with monitoring changes in your horse’s eating and drinking patterns will keep your horse moving easily from season to season and in good digestive health.

Low Starch Diet Benefits All Year Round

Compared to what’s known about seizures in humans and small animals, there’s surprisingly little data about seizures in horses. In addition, veterinarians and owners use many different terms to describe the disorders. To further collective knowledge, a research team recently undertook a study aimed at better defining this relatively rare equine disorder.

Led by Véronique Lacombe, PhD, DVM, Dipl. ACVIM, associate professor at Oklahoma State University’s Center for Veterinary Health Sciences, the team studied information available for 104 horses admitted to The Ohio State University Veterinary Medical Center for seizures between 1988 and 2009.

Through the review, researchers were able to begin defining equine seizures and epilepsy, a chronic neurologic condition. Per the definition used in other species, epilepsy was defined as having two or more seizures. For the study, horses were considered epileptic if they had suffered two or more seizures at the time of admission to the hospital. Of the 104 horses, 70% were identified as having epilepsy.

In analyzing the available data, the researchers classified epilepsy in three categories: symptomatic, idiopathic, and cryptogenic. They diagnosed about a third of the horses with symptomatic epilepsy, meaning researchers identified a structural brain disorder (including tumors and other lesions) that caused seizures to occur.

The team determined that 2.7% of the seizures were caused by idiopathic epilepsy. These horses had a suspected genetic predisposition.

The third classification was cryptogenic epilepsy, meaning there were no identifiable causes. The researchers determined more than half the study horses (54%) had cryptogenic epilepsy because all their diagnostic test results were normal.

Additionally, the team found that horses with generalized seizures in which both sides of the brain were involved were seven times less likely to have epilepsy than those that had partial seizures, localized to one part of the brain.

Explore the power of the human-horse connection as you travel the emotional journey that veterinarians at Rood and Riddle Equine Hospital and owners embark on when a beloved horse becomes ill in Equine ER

Finally, researchers identified and classified “reactive seizures,” which are seen in horses with normal brain function suffering from a temporary systemic disease, such as hepatic encephalopathy.

“It’s a first step in the classification of seizures and characterization of epilepsy in horses that could help veterinarians in establishing a diagnosis, therapeutic plan, and prognosis for seizures,” said Lacombe.

A good run-in shed, whether simple or elaborate, should follow some basic design concepts

When I moved to Kentucky in 2005 I had great plans to build the perfect horse barn on our new property. I envisioned a structure with lots of masonry and large timbers to match what was all around me. After all, beautiful horse farms were part of what drew us to the Bluegrass in the first place.

My, how things change. In our case functional and flexible won over these loftier plans, but we couldn’t be happier with the result. Let’s face it: What does a horse really need? Beautiful barns are a monument to horses’ human caretakers rather than to the horses themselves. Wild horses were nomadic creatures of the steppes and windblown plains, superbly suited to extreme temperatures and weather. Subsequent domestication has developed an animal more suited to human endeavor, but still not far removed from his ancestors.

Horses tolerate heat and cold much better than their human handlers. However, in most climates horses do need to have shelter available from wind, precipitation, and sun. Inevitably, inclement weather blows in while you are not at the farm. Blankets that were too hot on horses earlier in the day can become soaked inside and out. If the horse is clipped for competition or other athletic endeavors, the natural defensive barrier of winter hair coat has been removed. Clearly, these horses do need a little help from their friends; a run-in shed could be that solution.

You might have a barn and simply wish to augment turnout with basic shelter for your herd; you might be considering temporary housing until you have the time and/or money to build a barn; or you could be reconsidering the need for a full-sized barn altogether. A highly adaptable run-in shed might be just what you are looking for and can meet any of these needs at a price that won’t break the bank.

Basic Design Concepts

The same general rules apply to all kinds of horse housing–whether elaborate barns or the most basic run-ins. One of the most important decisions is where to place the building. Good natural drainage away from the building pad on all four sides is essential for horse health (as it reduces standing water and mud accumulation) as well as building longevity. If you build on the side of a slope, make sure you can cut the grade down on the high side to cause runoff to go around the shed instead of through it. Also consider convenient access to the shed for occasional maintenance, as well as its proximity to water and electric and the costs involved.

Once you have determined your shed’s general location, consider the prevailing winds. Our forefathers knew exactly how the winds worked on their farms and situated their buildings accordingly. Now this essential information is not as obvious to those of us who spend our days inside or working off the farm. Typically a three-sided structure, the run-in should be oriented to protect horses from wind-driven rain and sleet as well as the sun. If prevailing winds are out of the Southwest, for instance, the open side of most well-planned run-ins will face to the North or Northeast. This provides shade as well as wind protection except for the rare storm out of the Northeast. A south-facing open-faced shed will need a substantial overhang to provide adequate shade.

“Besides providing shelter, run-ins provide a useful means of catching and containing horses in need of medical examination or treatment,” adds Eric Peterson, DVM, an equine practitioner in Lexington, Ky. “They need to be large enough to allow the animal to turn around and avoid injury as they are caught, but not so large that other horses turned out in the same field interfere with the process.”

When constructing one of our run-ins, for instance, we centered it on a fence row with a flexible gate system that allows access to two different pastures or both. This allows us to segregate animals when we need to. Each half of the run-in is 16 feet wide–large enough to stand alone as protection for a few horses. By installing swinging gates in front of the run-in we can also open the full 32-foot width to either pasture when rotating. In the winter when we open both pastures we simply remove the gates to allow access from either pasture. This size accomodates six or more horses easily when fully opened. We rotate cattle and horses on our pastures and both benefit from the protection it affords.

When determining your run-in’s size, consider the number of horses that will be turned out at any one time. Horses need room to escape each other when they all want to be in the shed. A good general rule is to allow two horses per equivalent stall size of about 12-by-12 feet (i.e., a run-in for four horses would have 12 by 24 feet of space). These are loose rules that vary by horse breed and size; simply remember that crowding too many horses into a run-in is dangerous for horses and handlers and potentially damaging to the structure.

Herd dynamics should also affect run-in size decisions. According to Bob Coleman, PhD, PAS, associate director for undergraduate education in equine science and management and extension horse specialist at the University of Kentucky, another rule of thumb for shed size is 100 square feet of space per horse for the first two horses using the shelter and 50 square feet for each additional horse.

The shed walls should be a minimum of eight feet high at the low (back) side. The pitch of the roof depends on personal taste and climate requirements, but generally it should not be less than 4 ½ or 4 inches of rise for every horizontal foot. The rise in the roof toward the open end will create a taller wall at the front of the shed. Often the front wall is left open up to eight feet high and sided above to ¬increase shelter from sun or precipitation.

Materials

Run-ins can be built from any of the same materials used for horse barns. Masonry is durable but expensive. Wood is less expensive but requires more maintenance. In any case, remember the horse will have access to both the inside and outside of every wall, so the building must be sturdy enough to withstand the occasional kick and should have no sharp edges on which a horse could scrape or cut himself. Metal-sided run-ins, the least expensive in most regions, should be lined with wood inside to prevent a horse from kicking through the walls and sustaining a serious injury. Also eliminate sharp siding edges.

Prefabricated metal structures can be the quickest housing solution, shipped straight to your site. Use care, however, to fasten these structures securely to terra firma to prevent wind damage. Run-in sheds as a whole are not designed to be portable. But many owners will move the sheds regularly (which often weakens the structure) or do not fasten them down sufficiently to endure wind and weather extremes.

The reason these buildings are called run-ins is because horses can and do run in when looking for shelter. Therefore, the footing needs to be a nonslip material. A run-in’s floor is typically natural earth augmented with at least 4 inches of Class I sand or a similar material–preferably atop geotextile fabric to reduce sand loss due to water runoff. This will provide a tough, easy-to-clean surface that will withstand pawing and exposure to urine. Some owners build a high-traffic pad (made of geotextile fabric, No. 4 crushed stone, and a dense grade aggregate installed over an excavated area) for drainage and then place the run in shed on the pad, adds Coleman. Shavings can be used as a topper, but soiled shavings should be removed on a regular basis to avoid moisture buildup. Also remove manure to prevent flies from gathering and breeding, though the need will be less frequent than in barn stalls since horses are not confined.

Case in Point

When we decided to build a free-standing run-in shed, we set a budget of only a few thousand dollars. We used six treated 6-by-6-inch posts set in concrete to create two bays, 10-by-16 feet each. We then built the roof with a front overhang to increase the sheltered area to approximately 14 feet in depth. The idea was to maximize roof area while keeping the front of the side walls far enough back to reduce the chance of a horse being trapped in a corner by an aggressive pasturemate. The overall shelter area was large enough for the six or so horses we anticipated would use it. The pitch is 7/12 (seven inches vertically per 12 inches horizontally), primarily for aesthetic reasons. Two large beams support the front roof structure because of the combined load of the main roof framing and the front overhang. The walls are constructed of vertical rough-sawn 1-by-6-inch lumber attached to horizontal framing material attached to the posts. We used hot dipped galvanized nails for all fasteners, and added a shingle roof to match other structures on the farm. Metal also would have worked well.

This run-in shed is now well over 10 years old and has required no maintenance other than cleaning out the manure and replacing the footing with fresh Class I sand every few years. Also, as in all our equine housing, we check regularly for loose nails, sharp edges, or other obvious hazards.

We chose not to run power or water to this run in because of its proximity to the barn and outside float waterers, although many owners opt to add these for convenience. Another common addition to this basic design is a hay storage area, often as a center room between two run-in areas. These vary from a few partitions made from pipe gates to fully enclosed rooms. This arrangement is particularly useful if your horses are housed in the adjacent pastures for extended periods of time. Water at the shed might be useful for the same reason, although if you use a frost-proof hydrant, it should be separated from the turnout area to avoid potential injury.

An alternative run-in concept is one created from a portion of an existing structure.

Take-Home Message

The main appeal of the run-in concept is the horse’s freedom to move about at will without human interference. You can design your shed as elaborate or as basic as you like and still adhere to this concept. A run-in shed’s flexibility is what makes it one of the most useful structures on a farm.