How to Manage a Fat Horse and Help Him or Her Lose Weight

A horse needs to be at a healthy weight for his body to function correctly. Obesity can cause a wide range of performance-related problems and diseases. It’s also prevalent in pleasure horses across the world, with studies showing that nearly half the horses in the UK are either fat or very fat. 

A vet from the UK once described to me how some of the horses he examined were so overweight that the movement of their crests made it problematic when it comes to establishing their level of soundness.

How can you help a fat horse lose weight? Help your horse lose weight by reducing your horse’s calorie intake and gradually increasing his exercise to help him lose excess weight safely. The most effective approach is to create a balanced management regime that corresponds to the underlying cause of his weight gain. 

The first step towards solving the problem is recognizing it.   

Determining if Your Horse is Overweight

It’s tempting to believe that any horse with a big belly is overweight, but this isn’t necessarily true. 

What is considered fat for a horse? You can determine if your horse is overweight by using the Hennecke body condition scoring system. This visual and physical examination assesses the amount of fat present in critical areas of the horse’s body. 

We detailed this system’s nine categories in our article on How to Bulk up your Horse with Muscle and Weight.  In summary, a horse with fat deposits along the neck, around the withers and shoulders, and over the ribs and back would benefit from losing weight. 

You can also use a weight tape (Amazon) to get a rough idea of your horse’s weight and use the table below to compare that to the optimum weight for different breeds. Please note that this is not a scientific resource and shouldn’t be relied upon as the only method for determining if your horse is overweight.

Optimal Horse Weight by Breed:

Height	Pony	Arabian	Quarter Horse	TB	L/W Hunter	M/W Hunter	H/W Hunter	Draught
12hh	440lbs
13hh	660lbs
14hh	770lbs	880lbs	990lbs
14.2hh		935lbs	1050lbs
15hh		990lbs	1100lbs	880lbs	990lbs
15.2hh		1100lbs	1150lbs	990lbs	1100lbs	1100lbs
16hh		1100lbs	1200lbs	1100lbs	1200lbs	1200lbs	1400lbs	1500lbs
16.2hh			1300lbs	1200lbs	1200lbs	1200lbs	1400lbs	1650lbs
17hh				1300lbs	1300lbs	1300lbs	1500lbs	1850lbs

Using the Cresty Neck Score to Determine Obesity

The standardized Cresty Neck Score can help you establish if insulin resistance is causing your horse’s weight gain. This approach requires a visual and physical assessment of the fat deposits along the neck. These are associated with increased insulin resistance, which may increase the horse’s risk of laminitis and Equine Metabolic Syndrome (EMS).

The Cresty Neck Score uses six categories:

#0 A healthy horse will have no visible crest. There will be no movement or flexibility along the top of the neck when palpitated.

#1 There is no visible crest, but you will feel a slight filling when performing a physical examination.

#2 The crest is visible and shows an even fat distribution from the poll to the withers. The crest will feel flexible and move from side to side when palpitated. 

#3 The crest is thick throughout, with a larger fat deposit in the center of the neck. It is no longer as flexible and fills a cupped hand.

#4 The enlarged crest is thickened to the extent that creases may be visible along its top line. It is inflexible and too large to cup with one hand.

#5 The crest is so enlarged that it droops to one side.

9 Problems Associated with Obesity in Horses

Just as with any animal, overweight conditions can cause many health problems. 

What happens when a horse gets too fat?

Obesity in horses has similar health implications as it does for humans. It puts increased pressure on the heart and lungs, joints, and hooves. Overweight horses are also more prone to various diseases, including EMS, Hyperlipidemia, Laminitis, and Cushing’s syndrome. Horse obesity impacts hoof, joint, and muscle health. Let’s dive in. 

#1 Equine Metabolic Syndrome 

Closely associated with insulin dysregulation in horses, EMS can cause horses to gain weight. Obese horses are also more likely to develop insulin resistance, although the exact causes of EMS are unknown.

It is difficult to distinguish an obese horse from one with EMS. Both develop fat deposits on the crest and rump, and both are more susceptible to laminitis. A horse that looks overweight urinates and drinks more than usual could be suffering from insulin dysregulation.

Horses suffering from EMS struggle to regulate their blood insulin levels correctly, causing a build-up of fat deposits. This makes it more difficult for them to lose weight.

Some breeds of horses are more susceptible to this condition than others. Breeds like the Arabian, Mustang, and Morgan that evolved to survive in harsh conditions appear particularly predisposed to EMS than high-maintenance breeds like the Thoroughbred or Freisian.

Breeds like the Arabian and Mustang are very efficient at utilizing glucose. This ability enabled them to maintain healthy energy reserves even when food was scarce. Unfortunately, it also means that a carbohydrate-rich diet, coupled with a limited exercise regime, means they consume too many calories. This excess causes them to gain weight and inhibits their insulin regulation. 

As yet, not enough is known about EMS or about the external and internal factors that influence a horse’s metabolism. Physiological factors, such as age, breed, and gender, all appear to contribute to the condition, as do environmental conditions.

As a horse with EMS can’t respond to insulin correctly, the pancreas releases more than necessary. This replicates the metabolic issues seen in humans with type-2 diabetes.

Common problems associated with EMS include hyperlipidemia, which causes a negative energy balance, and laminitis. 

#2 Hyperlipidemia

Hyperlipidemia occurs when lipid or fat concentrations in the blood become elevated. It disrupts the internal processes, causing the horse’s body to believe it’s in a state of starvation. It responds by releasing excessive amounts of stored lipids into the bloodstream. As the condition worsens, the horse will suddenly lose weight, no longer show any interest in food, and show signs of lethargy and weakness.

As hyperlipidemia puts such extreme pressure on the liver, it has a high mortality rate. Early veterinary intervention is needed to give a horse with hyperlipidemia the best chance of survival. Unfortunately, the condition can develop very suddenly, making it difficult to treat in time.

#3 Laminitis

Obese horses are more susceptible to developing laminitis, although horses suffering from obesity and insulin resistance are the most in danger. Laminitis occurs when the tissue (laminae) between the hoof and the coffin bone becomes inflamed and damaged. In severe cases, it can cause founder, in which the coffin bone separates from the hoof wall. 

Laminitis is irreversible and extremely painful. The only treatments available involve minimizing further progression and pain management. A horse that’s experienced a mild episode of laminitis has a good chance of recovery if the coffin bone is not displaced. More severe cases, in which founder has occurred and the coffin bone rotated, have a poor prognosis.

#4 Equine Cushing’s Syndrome

Pituitary pars intermedia dysfunction (PPID) or Equine Cushing’s syndrome is associated with the inappropriate production of hormones by the pituitary gland. 

The hormonal imbalance causes the following symptoms:

• A long, shaggy coat throughout the year
• Excessive sweat
• Lethargy
• Increased water intake
• Frequent urination
• Increased appetite
• Pot-bellied appearance
• Loss of muscle along the topline 
• Laminitis

Equine Metabolic Syndrome and obesity increase a horse’s susceptibility to Cushing’s syndrome.

A horse with Cushing’s will need treatment for the rest of its life and, even then, may experience recurring episodes of laminitis. 

Despite that, a clearer understanding of the syndrome has improved the prognosis of horses with Cushing’s. With the correct treatment, many live healthy and productive lives.

In addition to these diseases, obesity in horses can impair both performance and bodily function. Overweight horses are liable to experience:

#5 Poor Hoof Health

An overweight horse places more pressure on hooves, potentially impairing the compression and expansion of the digital cushion within the hoof. This causes inflammation and restricts blood circulation. 

As the hoof swells, increased pressure is placed on the hoof wall. The hoof wall may crack or even crumble as it expands to absorb shock. As the hoof is compromised, additional pressure is placed on the joints. 

Fat, or adipose tissue, also produces compounds that cause inflammation in various parts of the horse’s body, particularly its hooves. This damages the vasculature within the laminae. This increases the risk of laminitis and compromising the hoof’s integrity.

#6 Joint Problems and Osteoarthritis

Researchers maintain that overweight horses secrete inflammatory mediators that may “contribute to the development of obesity-related inflammatory disorders such as osteoarthritis.”

Fat horses are particularly prone to developing arthritis in the hock, coffin joint, and navicular.

Weight loss can help tackle some of the problems associated with osteoarthritis and alleviate pain and lameness. A horse with arthritis will also benefit from treatments that slow the cycle of inflammation, reduce stiffness and pain, and encourage cartilage regeneration. 

#7 Muscle, Tendon, and Ligament Strain

A horse that’s carrying excess weight exerts more pressure on his muscles, as well as his hooves and joints. He’s also more likely to experience soft tissue injuries in the form of strained tendons and ligaments. 

#8 Overheating

Overweight horses struggle to control their body temperature. The excess fat accumulates under the skin and around the vital organs, trapping in heat. Obese horses are more susceptible to overheating and need more careful managing in extreme heat.

#9 Increased Stress on Heart and Lungs

In obese horses, the increased body mass restricts the expansion of the chest wall. This means they may experience alterations in blood flow, problems with circulation, and potential heart problems. It’s also likely that overweight horses are more likely to develop heart disease and cardiac arrhythmias (irregular heartbeats). 

Researchers at Texas A&M University are currently investigating the possible link between obesity and asthma. Equine asthma is a relatively common and debilitating problem that affects horses between 10 and 20%. The limited treatment options and the severe impact on the horse’s quality of life make it particularly worrying.

Factors that Contribute to Weight Gain

Some horse breeds are more susceptible to EMS, and others are more prone to obesity. A study conducted in the UK in 2014 identified breed as the most significant risk factor linked to obesity. Native UK cobs are at a higher risk of obesity, along with native pony breeds like the Welsh and Exmoor.

Seasonal changes also have a significant impact on a horse’s weight. The prevalence of obesity was much more significant during the summer months (35.41%) than the end of winter (27.08%). This seasonal variation was particularly notable in horses on pasture. Obese horses, however, showed less seasonal variation in body condition than horses at a healthy weight. 

Curiously, the study found no direct correlation between a horse’s weight and his level of low-intensity exercise. Heavy workhorses can be just as overweight as those receiving no structured activity if they eat more than required. Nor was supplementary feed seen as a strong predictor of future obesity.

Studies have also found that obesity is more prevalent in older horses, possibly because older horses work less and therefore have lower energy requirements. 

As breed plays a significant role in obesity, “easy keeper” horses require a more structured and holistic approach to diet and exercise.  

How to Manage an Overweight Horse

As a horse owner, you need to be dedicated and consistent to effectively manage an overweight horse and reduce the risk of developing any of the problems explored above. 

Although advice from equine practitioners will help you manage your horse’s weight, the ultimate responsibility lies with you and your dedication to managing his nutrition and developing a regular exercise regime.

Feeding Practices That Help Your Horse Lose Weight

The study above found no clear correlation between supplementary grain feed practices and obesity, but can a horse get fat on hay? 

Many owners worry that giving their horses ad-lib access to hay or pasture will cause them to gain weight. Equine nutritionists say otherwise. 

Dr. Juliet Getty believes that reducing your horse’s access to forage is more likely to cause weight gain than giving him free access.

According to Getty, the stress associated with forage deprivation encourages your horse to store more fat. 

Why is my horse’s belly so big? Many horses develop a large stomach, also known as a “hay belly,” without becoming obese. A horse’s abdominal area distends to cope with a large volume of roughage in the form of hay or grass. Digestive issues and a heavy parasitic load can contribute towards this issue, but it’s not necessarily indicative of obesity. 

The quality of the hay also contributes to the size of the abdomen. A horse will retain poor-quality hay for longer to extract as much nutrition as possible. 

Horses will self-regulate the quantity of hay they eat. They may gain weight in the first couple of weeks of having access to hay 24/7. But, once they realize the supply won’t dry up, they’ll relax and regulate their consumption.

Rather than rationing your horse’s grain or hay intake, give him ad-lib access to high-quality forage. Use a ration balancer to ensure he’s getting the nutrients necessary for optimum health and performance. 

Having access to plenty of clean, fresh water will make the horse’s digestive system more efficient. This promotes the optimal function of the internal systems and enables the body to rid itself of waste products.

If your horse needs supplementary grain feed, select those that are lower in fat, sugar, and starch as these are less nutrient-dense. 

A combination of diet and exercise will help your horse lose weight and improve overall health.

Recommended Weight-Loss Exercises

Exercise is integral to managing an overweight horse. It has the following benefits:

• It burns up more calories,
• Decreases the amount of fat gained,
• Uses fat in the body,
• Improves performance by strengthening muscles, soft tissues, and bone.

If your horse hasn’t done any structured exercise in a while, he’ll be unfit as well as overweight. How do you handle a fat horse? Your exercise regime should consider both your horse’s fitness level and weight. Don’t ask too much of your horse initially. Instead, introduce exercise slowly and increase his activity level gradually.

Start with 30-minute sessions of walking two to three times a week. Gradually introduce some slow trot work and increase the duration and frequency of the sessions to one hour a day, three to five times a week. 

You can perform these initial training sessions either on the ground or under the saddle. Bear in mind that a horse will burn more calories under the saddle and be more prone to overheating.

Your horse should produce a light, visible sweat during each exercise session. Any more than that indicates over-exertion, which can put excessive pressure on the joints, hooves, tendons, muscles, and ligaments. 

Lunging is also effective as part of your weight-loss exercise regime. Again, start with walking only, gradually introducing and increasing some slow trot work as his fitness improves. Keep your lunging sessions to 30 minutes long, doing 5 minutes in one direction, 5 minutes in the other, and alternating throughout the session.

Don’t attempt any jumping exercises with an overweight horse as this is a high-level activity that places a lot of strain on his limbs and joints. 

Start with some simple groundwork if you’re keen to get your horse in the showjumping arena. Not only will this provide mental stimulation, but it will also work your horse’s core muscles and improve his suppleness in preparation for more advanced work later on. 

Walking poles are an ideal starting point, giving you the chance to control your horse’s stride length while building his muscle and burning fat. 

If you’re working in a circle, either on the lunge or under the saddle, using a fan of poles gives you three different tracks, with the middle one being the same as your horse’s natural stride. You can then use the inner and outer tracks to teach your horse to lengthen and shorten his stride, developing his muscles accordingly.

As your horse loses weight and builds fitness, you can raise the poles off the ground, giving him a more intensive workout. 

Above all, helping an overweight horse to lose weight requires patience. This is a process that takes months rather than weeks. Rushing the process is counterproductive. It is likely to end in injury that will require more rest, making weight gain even more challenging to control.

Conclusion

Obesity in horses is a dangerous condition. An overweight horse is more prone to certain diseases and will struggle to perform at his best. Low-maintenance breeds are more susceptible to obesity and require a structured management regime that combines a low-fat diet with regular exercise.