A healthy digestive system plays an important role in your horse's overall wellbeing. The intestinal lining does much more than absorb nutrients. It also acts as a protective barrier, helping regulate what passes from the digestive tract into the bloodstream.
When this barrier becomes compromised, intestinal permeability can increase. Often referred to as leaky gut, this describes a situation where the intestinal lining becomes more permeable than normal, allowing substances such as bacterial components and other compounds within the gut to pass across the barrier more readily.
Research has explored intestinal permeability in horses and its relationship with digestive disturbances, inflammation and changes to the gut microbiome. While the term 'leaky gut syndrome' is commonly used, it isn't a clearly defined standalone diagnosis in horses. Understanding the factors that influence gut health is an important starting point for supporting your horse's digestive system.
Causes and Contributing Factors
Several dietary, environmental and management factors can affect the intestinal lining and the balance of microorganisms within the horse's digestive tract.
Dietary Factors
A horse's digestive system is designed to process a high-fibre, forage-based diet. Problems can arise when feeding practices place too much pressure on the digestive system.
Factors to consider include:
-
Excessive grain and starch intake
-
High intakes of sugars and fructans from pasture or feed
-
Sudden changes in diet
-
Inadequate fibre intake
-
Poor-quality or mouldy feed
-
Imbalances in the overall diet
High-sugar intake can be particularly problematic for horses prone to metabolic issues or laminitis.
When large amounts of starch or fructans reach the hindgut, they can ferment rapidly, altering the microbial balance and lowering the pH. This can disrupt beneficial fibre-digesting bacteria and contribute to hindgut acidosis.
High-protein feeds, including lucerne, aren't automatically harmful to the gut. However, the overall diet needs to be balanced according to the individual horse's requirements. Similarly, dietary fats aren't inherently damaging, but excessive supplementation or sudden changes can affect feed balance and digestive tolerance.
Grains also contain naturally occurring compounds such as lectins. However, it's not established that dietary lectins are a common cause of intestinal permeability in horses, so it's more useful to focus on the overall quality, balance and suitability of the diet.
Other Contributing Factors
Other factors that may influence intestinal barrier function and digestive health include:
-
Parasite burdens
-
Prolonged stress
-
Intestinal inflammation or infection
-
Sudden dietary changes
-
Certain medications, including non-steroidal anti-inflammatory drugs (NSAIDs)
-
Disruptions to the gut microbiome
-
Chemical sprays used on pasture weeds
Prolonged stress can affect digestive function and the gut microbiome. Certain medications can also influence the intestinal lining. Research in horses has shown that NSAIDs, particularly with prolonged or inappropriate use, can affect gastrointestinal health and intestinal barrier function.
It's important to consider the horse's full management history, including medication use, parasite control and any recent changes to its diet or environment.
Symptoms to Look For
Changes in intestinal permeability can be difficult to identify because the signs aren't specific to one condition. Digestive disturbances and changes in gut health can present in several ways.
Possible signs include:
-
Digestive disturbances: Loose manure, diarrhoea, recurrent mild colic or changes in manure consistency.
-
Weight and appetite changes: Poor appetite, difficulty maintaining weight or unexplained weight loss.
-
Changes in condition: Dull coat, reduced vitality or poor overall condition.
-
Behaviour and performance: Lethargy, unsettled behaviour or a change in usual performance.
-
Recurrent digestive issues: Ongoing sensitivity to dietary changes or repeated digestive disturbances.
These signs can have many possible causes, so they shouldn't automatically be attributed to leaky gut.
The Connection Between Gut Health and Laminitis
One area worth paying attention to is the relationship between hindgut health and laminitis.
When large amounts of starch or fructans are rapidly fermented in the hindgut, the resulting changes in acidity and microbial balance can contribute to intestinal disturbances. In some circumstances, this process can trigger inflammatory responses associated with laminitis.
However, laminitis has several different causes. Insulin dysregulation and pasture-associated metabolic issues are particularly important contributors, so it's not accurate to suggest that leaky gut is the main cause of laminitis.
Maintaining a healthy digestive environment and managing dietary sugars and starches are important parts of supporting horses prone to laminitis.
You can read more in our article about watching for laminitis and founder.
Management and Supporting Gut Health
Supporting intestinal health involves looking at the whole horse, particularly diet, forage quality, daily routine and environmental stress.
1. Feed a Natural, Forage-Based Diet
The foundation of a healthy equine diet is good-quality forage.
-
Feed a balanced diet based around suitable, high-quality forage.
-
Prioritise fibre and avoid excessive grain and starch intake.
-
Consider the sugar and fructan content of pasture and hay, particularly for horses with metabolic sensitivities.
-
Avoid sudden changes in feed.
-
Ensure protein and fat intake are appropriate for the individual horse.
-
Provide consistent access to suitable forage throughout the day.
For horses prone to metabolic issues, testing forage for sugar, starch and fructan content can help guide feeding decisions.
Our guide to a natural diet for horses explores the importance of feeding according to your horse's individual needs.
2. Support a Healthy Gut Environment
The horse's gut microbiome contains a complex community of bacteria and other microorganisms that help break down fibre and support normal digestive function.
Maintaining a suitable environment for these microorganisms is important. Consistent feeding routines, adequate fibre and avoiding excessive starch intake all help support a balanced hindgut environment.
Probiotic products may also be considered as part of an overall nutritional approach.
3. Reduce Stress
Stress can influence digestive function, so consider your horse's daily routine and environment.
-
Provide regular turnout and movement.
-
Maintain consistent feeding times.
-
Avoid unnecessary changes to their routine.
-
Encourage social interaction where appropriate.
-
Allow sufficient time to settle into new environments or management arrangements.
Regular movement and access to forage help support normal digestive function.
4. Consider Individual Nutritional Needs
Every horse is different. Age, workload, body condition, metabolic status and existing digestive issues all influence their nutritional requirements.
A horse experiencing ongoing diarrhoea, recurrent colic, significant weight loss or other persistent symptoms needs further investigation rather than assuming intestinal permeability is the cause.
Supplements to Support a Healthy Gut
Alongside a suitable diet and good management, certain nutritional ingredients and herbs can be included as part of a broader approach to digestive wellbeing.
Probiotics
Hi Form BioEquus is a probiotic product for horses. Probiotics are used to provide beneficial microorganisms as part of a nutritional approach to maintaining a balanced gut microbiome.
Slippery Elm Bark
Slippery Elm Bark Powder contains mucilage, a naturally occurring substance that forms a soothing gel when mixed with water. Slippery elm is traditionally used in herbal nutrition for digestive comfort.
Flaxseed and Chia Seeds
Greenpet Linseed (Whole Flax Seeds) and Chia Seeds provide fibre and naturally occurring fatty acids. They can add nutritional variety to a horse's diet and provide an alternative source of dietary fats.
B Vitamins
Vitamin B12 and folate (vitamin B9) are involved in normal metabolic processes. Their suitability as supplements depends on the horse's overall diet and nutritional requirements.
Soothing Herbs
Several herbs are traditionally used in equine herbal nutrition to support digestive wellbeing.
These include:
These herbs are all included in our Herbal Equine Gut Blend.
The most suitable combination will depend on your horse's individual needs, diet and current health.
Conclusion
A healthy intestinal lining and balanced gut microbiome are important parts of your horse's overall wellbeing. Diet, forage quality, stress, medication and changes to the gut microbiome can all influence digestive health.
By prioritising a natural, forage-based diet, managing sugar and starch intake, maintaining a consistent routine and considering appropriate nutritional support, you can take a proactive approach to your horse's gut health.
If you're concerned about your horse's digestion or suspect their current diet isn't supporting them properly, we're happy to help.
Ask our Naturopath – our advice service is free.