For thousands of years, horses have been a source of fascination for humans, growing from wild roaming deities to one of our most vital working, sporting, and companion animals. But the key to their power and endurance is more than training; it’s a highly specialised physiology. To appreciate and manage these creatures, it’s not enough to merely look at the horse; it’s about understanding the balance of nutrition, biomechanics, and health needs that make up their daily lives.
In this, the first part of our in-depth look at horse health, we examine the most important aspect: equine nutrition.
A History of the “Trickle Feeder”
To answer the question, “What do horses eat?”, it’s important to first consult the equine anatomy. Horses are “trickle feeders”, as opposed to humans, who have several meals per day. In nature, horses are on the move feeding for around 16-18 hours per day. They are adapted to eat small amounts of high-fibre, bulk feed.
Horses have a relatively small stomach – the size of a large football. This means they can only eat small meals. Instead, food rapidly enters the small intestine before reaching the enormous cecum, where fiber is fermented. This helps keep the digestive tract moving, which helps prevent life-threatening disorders such as colic.
Caption: A diagram of the equine digestive tract illustrating the small stomach capacity and the large cecum where fiber fermentation occurs.
Forage: The Key to All Diets
If you ask a vet or nutritionist what component of a horse’s diet is the most important, they will all say forage. Forage is pasture and hay. For most horses, good quality forage should form the basis of 1.5% to 2% of their body weight per day.
With an average weight of 1,000 pounds (or 450 kg), this equates to eating 15 to 20 pounds of hay or grass per day. Forage contributes the fibre that’s needed to allow fermentation in the horse’s hindgut, which produces heat to keep it warm and supplies its energy needs. A lack of forage can lead to gastric ulcers, “cribbing” and other behavioural problems, and severe stomach upset.
Supplements and Grains
Forage is the mainstay, but sometimes it’s not sufficient. So, concentrates (oats, barley, corn, or commercial pellets) are used. But grains are best used as an add-on.
Race or Show Horses: Eventing, jumping, or racing horses need more calories to fuel their performance.
Foals and Seniors: Young and old horses may need additional protein and fats to help them grow or to prevent them from wasting away.
Easy Keepers: On the other hand, many “pleasure” horses are quite happy just eating grass, and can get fat if given too much grain.
When feeding concentrates, “small amounts, often” is a good rule of thumb. Feeding a large grain meal at once can overfill the small stomach and cause excess starch to reach the hindgut, leading to painful gas and/or laminitis.
Vitamins, Minerals, and Salt
Pasture, even of high quality, may be lacking in some minerals, depending on the area’s soil. Coat, hoof, and immune condition depend on the trace minerals selenium, copper, and zinc. Trace minerals are usually provided by the horse owner, who will offer a “ration balancer” or a simple salt block with trace minerals.
Salt is particularly important. Like humans, horses are among the few animals that sweat when stressed. This results in electrolyte loss. The horse needs a steady supply of salt to drink sufficient water to keep him well hydrated to deal with the dry forage he’s eating, which has to travel through his digestive system.
Toxic Territory: What to avoid
Part of knowing about horse nutrition is knowing what’s poisonous. Horses cannot vomit, so if they do ingest a toxic substance, it must travel through their system, and can cause permanent damage or death.
Onions, garlic, chocolate, and caffeine are just some of the foods that humans enjoy that must be avoided. Additionally, some plants in the garden, such as Foxglove, Yew, and even Red Maple leaves, are deadly in small quantities. It is also important to know what is in your horse’s surroundings and the quality of his hay.
Understanding that the horse is a continuous forest browser and ensuring you feed the best-quality hay and pasture possible will keep your horse healthy and happy. Today, in Part 2, we will explore the physical beauty of the horse and answer the question: Can horses swim?
Swimming with Horses & Motion in Action
Nutrition fuels the horse; the horse’s physical abilities are what make it truly majestic. In this installment, we leave the gut and head to the water for an equine lesson on locomotion. Among the questions most often asked by horse lovers and new owners is: Do horses swim? The response can tell us a lot about horse biology and its use in veterinary practice.
The Instinct is Strong: Swimming Horses
In a word, yes – horses are instinctive swimmers. Rather than needing to learn to swim, as many humans do, horses have a natural instinctive response to swim when they are not in contact with the ground. When horses dip their feet into deep water, they automatically lay down their head and neck, and start “dog-paddling”.
It’s a trait that comes from their evolutionary past. In the wild, horses needed to swim to avoid predators or find new sources of food. Their enormous lungs function as built-in life jackets, supporting their weight in water, allowing their muscular limbs to propel them. In fact, although they are good swimmers, they do not “div” (keep their noses out of the water); instead, they keep their heads above water to breathe.
Healing & Rehabilitation: Hydrotherapy
Today, swimming is not only a life-saving skill but a complex exercise and therapy for horses. Due to the average weight of a horse (often over 1000 lbs), their joints and tendons are always at work during ground training.
Swimming offers a non-weight-bearing and high-resistance exercise. The horse’s weight is supported by the water, eliminating the shock of its weight on the lower limbs. It’s an excellent rehabilitation exercise for:
Healing Tendon and Ligament Injuries: Enabling the horse to exercise to keep its cardiovascular system in shape while recovering.
Developing Topline Muscles: The horse must use the muscles in its back, neck, and hindquarters more than when working on land.
Lung and Heart Fitness: Swimming causes the horse to breathe more deeply and can build lung and heart capacity.
A horse undergoing hydrotherapy, demonstrating how water buoyancy provides a low-impact cardiovascular workout for muscle recovery.
Safety and Limitations
Although a natural talent for a horse, swimming can be tiring. Just a few minutes of rapid swimming may be similar to running several miles on land. It’s important for owners to be aware of fatigue; a fatigued horse can begin to sink in the back, which can result in panic and drowning.
And not all water is created equal. If taking a horse to a lake or beach, it is important that the shore is solid and sloping. Slippery or steep inclines can cause the horse to slip and injure itself. It is also important to remove tack, such as saddles, which can be dangerous because they can weigh the horse down.
The Magic of the Horse’s Leg
Horses are able to swim (and gallop at high speed) because of the “stay apparatus” in their leg. This network of tendons and ligaments enables a horse to “stay” its joints.
This adaptation of nature has two functions:
Standing to Sleep: It enables the horse to sleep (at least in light sleep) while standing, conserving energy and preparing to flee in case of danger.
Energy Saving: When the horse walks, the tendons spring into action, storing energy as the hoof strikes the ground and releasing it to assist the horse’s movement.
Coordination and Balance
Horses have remarkable balance, with their vestibular system and broad vision helping them maintain it. They are strong but fragile. A horse’s “sporting life” is reliant on their legs. So it is important to know the average horse weight and to manage it well, as being overweight places undue stress on this intricate machine, and may end a horse’s swimming or running days.
As we have learnt, horses are highly versatile animals. On land, they are perfectly adapted to roam freely, and in water, to swim. In Part 3, we will return to the weighing scale to discuss how to keep a horse at an ideal weight and why water and hydration are so important for this level of physical performance.
The Key Metrics – Weight, Water, and Hydration
The balance of the inner workings of the horse and the outward physical expressions of health needs to be carefully monitored. In this third article, we explore the crucial metrics of health: controlling the average weight of a horse and the essential function of water. Weight in horses is not merely a measurement of mass; it is a key gauge of metabolic efficiency, joint health, and vitality.
Getting to the Heart of the Matter: Average Horse Weight
A common misconception in horse care is applying a “one size fits all” approach to weight. But weight varies greatly with breed, size, and conformation.
Light Breeds: Thoroughbreds and Arabians are between 800 and 1,100 pounds.
Draft Breeds: Shires and Clydesdales weigh more than 2,000 pounds.
Ponies: Miniatures may only weigh 200-600 pounds
Being familiar with your horse’s weight is critical for administering medications and dewormers, and for determining appropriate feed amounts. But most horse owners don’t have access to a large livestock scale, so they rely on “weight tapes” that measure the circumference of the horse’s heart, or equations that combine the circumference of the heart and length of the horse, to calculate weight.
The Henneke Body Condition Scale
Body weight is not everything; a 1200-pound horse could be muscled up or fat. To overcome this problem, a Henneke Body Condition Scoring (BCS) system is used. This scores a horse between 1 (poor/emaciated) and 9 (fat) based on the amount of fat over the ribs, shoulder, neck, and tailhead.
Most horses should have a score of 4-6. Any horse with a body condition score of 7 or more is at a higher risk of developing Equine Metabolic Syndrome (EMS) and Laminitis – a terrible condition in which the soft tissues in the hoof become inflamed, often as a result of eating a diet high in sugars and carrying too much weight.
The Henneke Body Condition Scoring (BCS) system used to assess whether a horse is underweight, ideal, or overweight based on fat deposits.
Why Water is the Nutrient that is Often Overlooked
When it comes to horse nutrition, we tend to focus on what horses eat, but equally important is what horses drink. The daily water requirement for the average horse is 5-10 gallons. This can increase to 10-15 gallons a day during strenuous exercise and hot weather.
The digestive system is largely powered by water. Horses consume large volumes of dry feed, and need large volumes of water to keep the fiber moving down the 70-100 feet of intestines. Even slight dehydration causes food to move more slowly through the digestive system, and can cause “impaction colic”, a painful and potentially deadly blockage.
The Challenges of Water Intake
Horses don’t always thirst for water. The reasons for potentially deadly dehydration include:
Cold water: In winter, horses are less likely to drink water that is near freezing, which can lead to more colic in January and February.
Cleanliness: When water troughs are dirty (with algae, insects, or bird poo), it can make a horse reluctant to drink.
Travel: “Odd” water, which tastes or smells differently from the water back at the barn, may not be consumed by a horse.
For this reason, savvy horse owners often add apple juice or electrolytes to water when travelling to help mask the taste and prevent dehydration.
Electrolytes and Salt Balance
As covered in Part 1, salt makes you thirsty. Without sufficient sodium, the horse’s brain may not “recognise thirst” even when the horse is dehydrated. That’s why a salt block (or loose salt) is a must. In the summer, when horses perform strenuous work or are transported in a trailer, a balanced electrolyte supplement replenishes the minerals lost through sweat and helps the horse’s body cool.
Monitoring Output
The last healthy key is to check the output. Manure and its passage are direct indicators of hydration and gut health. Crumbling manure may indicate dehydration, while runny manure may mean a change in feed (such as a new hay) or a sugary pasture.
And with a keen eye on the weighing scales and water troughs, you can ward off most equine ills. In Part 4, our last in the series, we examine the significance of environmental health, stimulation, and exercise in the circle of wellness.
The Holistic Circle – Environment, Mind, and Maintenance
In Part 4 of our series on equine health, we will explore the role of environment and lifestyle in complementing a horse’s physical nutrition and weight for optimal health. Though we’ve answered the question of what horses eat and their surprising aquatic prowess, the last “powerful fact” is that horses are social, nomadic animals. In order for a horse to be well, both its psychological and physical environment must cater to its natural instincts.
Turn Your Horse Out: Movement is Medicine
Horses were not designed to be in a 12×12 stall. In nature, horses roam for miles each day, eating. It’s essential for their cardiovascular and digestive systems. Prolonged stall rest can cause a horse’s lower legs to “stock up” (fluid build-up).
“Turnout” – when a horse is able to spend several hours or a whole day in the pasture – encourages healthy joints, as the synovial fluid is kept in motion, and helps keep the average horse’s weight by exercising the horse. While the horse isn’t running, the walking it does to eat grass keeps the intestines moving, helping prevent impaction colic.
The Social Animal: Psychosocial Wellbeing
Horses are highly social, with a complex social structure. They don’t cope well with isolation. When completely isolated, a horse is likely to develop “stable vices”: compulsive, stress-related behaviours such as weaving, pacing, and chewing wood. These vices can be frustrating for the owner and damaging to the horse’s teeth and joints.
Social contact gives horses the stimulation they need, which humans can’t always provide. Grooming (allogrooming) decreases the horse’s heart rate and improves social cohesion. A calm and relaxed horse enjoys a lower heart rate, better immune response, and is easier to handle during training or veterinary treatment.
Hoof Care: No Hoof, No Horse
“No hoof, no horse” is the motto of horse ownership. The hoof is a living structure that bears the weight of the average horse (1000+ pounds) on a small hoof surface. Even if they are barefoot or have metal shoes, horses need their hooves trimmed by a farrier every 4-8 weeks.
Improper care results in hoof imbalances, which place stress on the tendons and ligaments discussed in Part 2. Good hoof care also includes routine everyday care by the owner, such as removing stones and other debris and checking for “thrush” – a fungal infection that arises from standing in wet or dirty conditions.
Dental Health and Feed Efficiency
For most of their lives, horses’ teeth continue to grow. They have a lateral grinding action, which results in the development of enamel points on the edges of their teeth. These can ulcerate the horse’s tongue and cheeks, resulting in an inability to chew its grass.
If the horse can’t chew its hay, it will not be able to extract the nutrients and will lose weight, no matter how much food is offered. Regular dental checks (or “floating” the horse – filing off the points) will allow a horse to get the most from its feed. This is especially important for older horses who may lose teeth and need “soaked” rations to maintain their weight.
A comparison between sharp enamel points that cause painful ulcers and healthy, “floated” molars that allow for efficient chewing.
Conclusion: It’s All about the Horse
Equine health is a 1,000 small choices. It starts with knowing what horses eat – encouraging fiber and fresh water for a healthy digestive tract. It is improved by appreciating their athleticism, from being able to swim to rehabilitate, to the need to move every day to maintain joint mobility. And it is sustained by valuing their body weight, their limbs, and their social structure.
If we remember that the horse is not just a tool for human use – sport, work, or even haberdashery – but an adaptive biological machine that has particular needs, we can get the most from our horse. When your horse is healthy, it is capable of great things, proving day in and day out that they are one of the most admired animals in the world. With these five pillars of power, you can be sure to have a healthy horse for many years to come.
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