Have you noticed changes in your horse’s appetite and eating behavior?

Perhaps your horse has gone off their feed or is no longer interested in eating as much forage as usual. Or maybe your horse’s appetite has increased, and they are going through their hay faster.

Your horse’s appetite can change frequently and for a variety of reasons. While short-term fluctuations are nothing to be alarmed about, longer-lasting changes can impact body condition and overall health.

Equine feeding behavior is complex and affected by many different factors. Your horse’s appetite is affected by temperature changes in the environment, activity level, gut function, reproductive status, feed composition, dental health, psychological well-being and more.

It’s important to know what is normal for your horse’s appetite and eating behavior so you can monitor for changes. Sometimes changes in appetite can signal a problem with your horse’s physical or mental state.

Feed Intake in Horses

Your horse’s appetite is primarily dictated by their energy requirements and their metabolic rate. [1]

When given free-choice access to feed, horses will spend 60% or more of their time on feeding behaviours. [1] Their time spent feeding will increase or decrease to maintain calorie intake.

Typically, horses consume between 1.5 to 3% of their body weight per day in feed and forage. This means that a 500 kg (1100 lb) horse will consume approximately 7.5 – 15 kg (16.5 – 33 lb) of dry matter per day.

If your horse is growing, gestating, lactating or exercising, their appetite will increase to supply the additional energy, protein and other nutrients required by physiological demands.

In healthy horses, how much forage they consume can also be influenced by forage quality. In general, mature forages with higher neutral detergent fibre (NDF) and lower crude protein are associated with lower intake. However, this is not always the case as some horses adapt to lower quality forage by increasing their intake. [24]

Therefore, it is critical to identify whether forage changes are the main cause of changes in appetite as these are typically only transient changes. Submitting a hay sample for analysis will help you determine if the hay has changed significantly and could explain altered intake.

Appetite Regulation

Appetite is controlled by hormones that are responsible for maintaining homeostasis within the body. Homeostasis refers to a steady state of internal, physical, and chemical conditions. [1][2]

In particular, the sensation of hunger is influenced by the hunger hormone ghrelin, which is produced by the ghrelinergic cells of the stomach. [3][4]

This hormone drives feeding behaviors, such as foraging and lowering the head to smell, taste, chew, and swallow food. Ghrelin is also involved in food selection. [1][5]

But many other factors can affect how much your horse is eating. Horses that are sore or unwell often lose their appetite as one of the first signs of an underlying problem, which is why it’s so important to keep a close eye on your horse’s eating habits.

Signs of Abnormal Appetite

Wild horses constantly seek out food to survive. Horses evolved to forage for 16-20 hours a day, consuming a variety of low-calorie roughage as they grazed large grasslands.

Under normal circumstances, horses will eat whatever feed is available and take any opportunity to consume extra calories. If a horse is not consuming the feed provided, there’s often a reason why.

Signs of an abnormal appetite and potential health issues may include:

  • Weight loss due to inadequate feed intake when feed is accessible
  • Increased appetite and excess weight gain if insulin resistance is present

Diagnosing a Change in Appetite

Whether your horse has stopped eating, reduced its feed intake, or increased feed intake, a veterinarian should be consulted to rule out any potential health problems.

To diagnose a problem with your horse’s appetite, your veterinarian will investigate for any medical conditions such as illness, pain, dental problems or metabolic irregularities.

Other important factors to assess include your horse’s exercise routine, living environment, feeding situation and the types of feed provided.

Why Has My Horse’s Appetite Decreased?

Have you noticed that your horse is dropping body condition or has lost interest in their feed?

A lack of appetite can signal gut health issues, dental disease, stress or problems with the forage or feed provided.

Sometimes, these changes are temporary and resolve on their own. Other times, veterinary intervention is required to address underlying health problems.

Gastric Ulcers

Inappetance may be a sign of Equine Gastric Ulcer Syndrome (EGUS). Gastric or stomach ulcers are common in horses, occurring in 60-90% of performance and pleasure horses.

Horses can develop gastric ulcers for a number of reasons, including dietary factors, exposure to stress, high-intensity exercise, environment, medication and more. [10]

Horses that have ulcers may show a wide range of signs including loss of appetite or anorexia (feed refusal). Other signs of ulcers include pickiness when eating, teeth grinding, weight loss, nervous disposition, dull coat, poor condition, recurring colic, poor performance, and aggressiveness. [10]

Hindgut Dysfunction

Ulcers can occur along the entire digestive tract, including in the hindgut. Ulcers that form in the hindgut are referred to as Right Dorsal Colitis (RDC) or colonic ulcers.

Hindgut ulcers are primarily associated with improper use of non-steroidal anti-inflammatories, but can also be caused by excessive acidity in the hindgut.

The hindgut can also be affected by a condition known as dysbiosis, which refers to a general imbalance of the microbiome of the gut.

Horses with hindgut dysfunction often go off their feed [is this true? – find ref] and may experience weight loss if they are not able to properly digest their feed.

Oral Ulcers

Some unprocessed feeds contain rough components (ie. hulls or seed heads) that can irritate your horse’s mouth and reduce feed intake. Hay may also be overly coarse or contain weeds with thorns or bristles that cause lesions in the mouth. [11]

These abrasive ingredients can contribute to inappetence by causing inflammation of the mouth and lips, ulcerative lesions in the mouth, drooling, and an overgrowth of gum tissue around the teeth (gingival hyperemia).

Have your veterinarian look inside your horse’s mouth to check for damage to oral tissues and consider using a different type of feed to prevent the problem.

Dental Disease

Various dental issues can cause pain and lead to reduced appetite and reluctance to eat feed. [12][13][14] Senior horses with worn teeth may also have reduced feed intake.

Oral examinations may identify sharp points on the molars or fractured and overgrown cheek teeth that can make eating uncomfortable.

Horses that act hungry but partially chew their hay and leave it in balls (referred to as quidding) around the feed area or stall may have dental disease that results in pain when eating.

Dental issues resulting in inadequate chewing of feed can also lead to maldigestion, esophageal impaction (choke) and intestinal impactions, all of which can contribute to appetite loss.

Pain and Illness

Horses that are in pain due to illness, infection, injury, lameness, or another condition may lose their appetite.

Assessment by a veterinarian is necessary to diagnose and treat any health conditions that are contributing to pain or soreness.

Colic

Horses with colic typically stop eating as this condition causes intense gastrointestinal pain. The stomach or intestines may become swollen, inflamed, obstructed and potentially twisted.

Aside from a loss of appetite, additional signs of colic may include stomach bloating, pawing at the ground, and rolling.

Colic may be caused by internal parasites, sand accumulation, dehydration, stall confinement, feeding practices and diets high in grains and pelleted feeds.

Intense Exercise

Exercise is known to alter hormone levels in the body, including increased cortisol and insulin.

These may induce changes in ghrelin levels, a hormone that stimulates hunger. It temporarily decreases after short bouts of high-intensity exercise which may explain temporary reductions in appetite following strenuous exercise. [3]

Stress

Stress can promote poor appetite and weight loss in horses. Your horse may experience stress due to moving to a different living environment, trailering, herd separation, or exposure to hot and humid weather.

Horses are happiest when living in a herd, but if they are low on the social hierarchy and bullied, they may become less interested in food because of stress. Horses at the bottom of the pecking order may also have less access to feed due to competition in group settings.

Poor appetite may also occur in horses that become depressed due to isolation, boredom or a lack of turnout.

Medication

Some medications can reduce your horse’s desire to eat either by affecting appetite and satiety signalling or by being unpalatable. For example, phenylbutazone (Bute) is a pain-relieving drug that can cause loss of appetite in horses.

Pergolide is often prescribed for horses and ponies diagnosed with pituitary pars intermedia dysfunction (PPID). [17][18] This drug acts on the dopamine receptors in the brain, which can cause low motivation for feed.

When receiving Pergolide, some horses show signs of reduced appetite or anorexia when the treatment begins. Their appetite typically returns to normal when the body adjusts to the new drug so long as the horse is on the correct dosage.

If a horse’s appetite loss persists while on Pergolide, the dosage may need to be adjusted or reduced temporarily.

Gastric Osmolality

Research shows that as gastric osmolality increases, horses stop consuming feed. [1] Gastric osmolality is a measure of the osmotic pressure of the stomach contents.

When osmotic pressure is high, fluid is drawn into the intestines. This promotes gastric emptying, or the emptying of food and fluid from the stomach into the small intestine.

Sudden Changes in Feed

Horses like a consistent routine that includes being fed at the same time each day. [4] They are also naturally very cautious when introduced to new feeds.

Any sudden changes in feed composition, texture, or smell could cause your horse to become hesitant when eating. Introduce new feeds or supplements slowly until the horse adapts to the new routine.

Poor Quality or Spoiled Feed

Horses have a keen sense of smell and can typically sense when feed has spoiled or contains mold. Feed left in an unclean or hot environment may spoil or ferment more quickly than feed stored in a clean and cool environment.

Research shows that horses eat less wheat when high levels of mycotoxins are present. Higher concentrations of the mycotoxin deoxynivalenol (DON) resulted in lower wheat feed intake in one trial. [23]

Treatments for Poor Appetite

Veterinary Treatment: If your horse has an underlying health condition such as dental problems, pain, infection, endocrine disease, or illness that is causing a poor appetite, veterinary treatment is required.

Change the Type of Feed: If your horse is not eager to eat despite a lack of medical issues, try gradually introducing a new feed to encourage eating. You can also work with an equine behaviorist on strategies to improve feeding behavior.

Feed a Higher Quality Forage: Select a more nutritious forage with higher levels of digestible fibre or add a legume hay such as alfalfa to your horse’s ration. Rough, stalky hay is also less palatable than broad, tender, leafy hay.

Feed Several Meals Per Day: Horses have a relatively small stomach and do best when fed many small meals several times per day. Provide constant access to forage to encourage eating throughout the day.

Correct Nutrient Deficiencies: Horses fed a diet experimentally deficient in the B-vitamin Thiamin were found to have reduced appetite. Ensure your horse is fed a diet with adequate levels of essential vitamins and minerals. [20]

Medications: Horses that undereat on a chronic basis may be prescribed medication to stimulate the appetite. Benzodiazepine derivatives (types of tranquillizers) can temporarily enhance appetite but can also cause side effects.

Management Techniques: Reducing stress in your horse’s daily routine can promote normal appetite. Some ways to reduce stress include:

  • Provide a cool bath when the weather is hot to help your horse feel more comfortable.
  • Temporarily reduce the intensity of your horse’s exercise program to determine if training stress is causing your horse’s change in appetite.
  • Provide your horse with sufficient turnout time to reduce stress.
  • Keep an equine buddy nearby to reduce anxiety and stress when your horse is eating.

Improve Digestive Comfort: Feed a supplement such as Mad Barn’s Visceral+ to support overall gut health and gastrointestinal function.

Visceral+ also contains yeast and digestive enzymes to help your horse absorb more of the energy and nutrients in their feed and reduce the risk of weight loss.

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Encourage Water Consumption: Adequate water intake is important to support your horse’s gut health and digestion. Feed salt to encourage thirst and provide plenty of fresh, clean water.

Add High-Fat Feeds: Fat is more calorie-dense and more efficiently metabolized than forage or grain-based feeds. Increasing the fat content of the diet can help to prevent loss of body condition in horses with a reduced appetite.

Add Palatable Feeds: Work with an equine nutritionist to make adjustments to your horse’s feeding program. Depending on your horse’s metabolic health, you may want to consider adding limited amounts of molassed beet pulp, sweet feeds, apple sauce, carrots, or other palatable feeds to increase calorie supply.

Flavoring Agents: A study of 48 horses of various breeds found that horses have preferences for certain tastes. The animals studied preferred pellets with a distinct sweet taste or slightly salty cereals. [15]

Another study found that the flavor of anise increases the palatability of feed. [16] Flavors including peppermint, fenugreek, caramel, raspberry and apple can also improve the palatability of concentrates. [19]

Why Has My Horse’s Appetite Increased?

Is your horse suddenly consuming more feed than usual? Increased appetite could be a result of a higher workload, changing physiological status or a sign of metabolic dysfunction.

Horses also experience seasonal variation in appetite, increasing feed intake during the summer when high-quality forage is abundant. [21]

Palatable Feed

Horses that are offered more palatable feed or grain have higher intake. [1]

Leptin Resistance

Leptin resistance often occurs in association with insulin resistance and may lead to increased appetite in obese horses. [6][7][8]

Further research is needed to understand the relationships between insulin, appetite, and leptin levels in horses.

Increased Energy Requirements

Horses that live outdoors during the winter consume more feed when the temperature decreases to maintain their core temperature without losing body condition. [9]

Appetite naturally adjusts to support the additional intake of energy during cold weather. [9]

Medications

Some medications, such as dexamethasone and prednisone, can increase your horse’s appetite as a side effect

Diazepam and promazine are pharmaceutical drugs that have also been found to increase appetite in equines. [22]

Presence of Other Horses

Research shows that horses eat more in the presence of other horses. [1]

Treatment for Overeating

If your horse’s appetite has increased, consult with your veterinarian to determine whether a medical condition may be the cause. Horses with metabolic syndrome or PPID may eat above what is normal for their energy requirements.

Horses that are overweight and have an excessive appetite due to insulin resistance may require medical treatment.

Management interventions for horses with increased appetite focus on reducing the calorie supply of the diet to prevent weight gain.

Remove High-NSC Feeds: Grain-based feeds and sweet feeds contain high concentrations of non-structural carbohydrates, including sugars and starches. Replace with low-NSC forages and feeds.

Provide Lower Energy Forage: Choosing a less energy dense hay will prevent excess weight gain in your horse. Select a mature cut hay, replace some hay with straw, and consider soaking your hay to remove excess sugars.

Regulated Feed Intake: Most horses will eat if provided free-choice access to feed. Some horses that are overweight may require controlled access to feed. Work with a nutritionist to determine an appropriate ration for your horse.

Extend Feeding Time: Forages that take longer for your horse to chew can extend feeding time and prevent over-eating. Your horse may benefit from a slow feeder hay net to reduce the rate at which they consume their forage.

Tips for Supporting a Healthy Appetite

You can help to support normal appetite regulation in your horse by following these management and feeding practices.

  • Work with an equine nutritionist to ensure your horse’s diet is balanced and there are no nutrient deficiencies. Submit your horse’s information online for a free evaluation.
  • Always provide your horse with access to fresh water and make sure that your horse’s water bucket is clean and filled daily. A dehydrated horse may be pickier about its food.
  • Feed your horse many small meals throughout the day instead of one or two large meals. Horses are natural grazers and evolved to eat continuously during the day.
  • Ensure that your horse’s food is fresh and of good quality. Select feed and forage that is appropriate for your horse’s body condition and energy requirements.
  • Have your horse assessed by a veterinarian to address health problems that could interfere with a regular appetite.
  • Have your horse’s teeth checked at least once or twice per year by an equine veterinarian or qualified equine dentist.
  • Reduce your horse’s stress by making diet and exercise changes gradually. Ensure your horse is not living/eating in stressful conditions (ie. competing for feed with aggressive herd mates).

If you have any concerns about your horse’s appetite, talk to your veterinarian so they can help you determine the cause and develop a plan to address it.

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Identify gaps in your horse's nutrition program to optimize their well-being.

References

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  4. Zupan M. et al. The Effect of an Irregular Feeding Schedule on Equine Behavior. J Appl Anim Welf Sci. 2020.
  5. Hanis, F. et al. Discovering the relationship between dietary nutrients and cortisol and ghrelin hormones in horses exhibiting oral stereotypic behaviors: A review. J Vet Behav. 2020.
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  10. Buchanan, BR et al. Treatment and prevention of equine gastric ulcer syndrome. Vet Clin N Am-Equine. 2003.
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  12. Jarvis, N. et al. Nutritional Considerations when Dealing with an Underweight Adult or Senior Horse.Vet Clin North Am Equine Pract. 2021.
  13. Rowley, KJ et al. A computed tomographic study of endodontic and apical changes in 81 equine cheek teeth with sagittal fractures. Equine Vet J. 2022.
  14. Dixon, PM et al. A review of equine dental disorders. Vet J. 2005.
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  16. Francis, JM et al. The Influence of Topically Applied Oil-Based Palatants on Eating Behavior in Horses. J Equine Vet Sci. 2020.
  17. Ireland, JL et al. Epidemiology of pituitary pars intermedia dysfunction: A systematic literature review of clinical presentation, disease prevalence and risk factors. Vet J. 2018.
  18. Harman, J et al. The role of nutritional therapy in the treatment of equine Cushing’s syndrome and laminitis. Altern Med Rev. 2001.
  19. Khelil-Arfa, H et al. Feed Concentrate Palatability in Welsh Ponies: Acceptance and Preference of Flavors. J Equine Vet Sci. 2021.
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