What Is Leaky Gut In Horses?

Leaky gut syndrome has been recognised in humans for several decades. The research in horses is extremely limited, so figures around how many horses have this, if any at all, are limited. However, let's delve into everything we do know. 

Leaky gut syndrome in horses occurs when the lining of the digestive tract is compromised, letting toxins, bacteria, and partially digested feed enter the bloodstream. In a healthy horse, the gut lining acts as a selective barrier—absorbing nutrients while keeping harmful elements out. When this barrier weakens, it can trigger inflammation and stress the immune system.

Understanding leaky gut is crucial because the gut influences immunity, behaviour, condition, and performance. Factors like stress, high-starch diets, medications, and illness can upset this balance. Recognising leaky gut early allows horse owners to take action and support long-term digestive health.

Leaky Gut Syndrome in Horses: Causes, Symptoms, and Treatment

Leaky gut, or increased intestinal permeability, happens when the gut lining can’t perform its barrier function effectively. Nutrients pass into the bloodstream, but harmful substances like toxins, bacteria, and undigested feed can also leak through. This triggers inflammation and strains the immune system, potentially causing broader health issues.

Common contributors include prolonged stress, high-starch or low-fibre diets, intensive training, illness, and certain medications such as NSAIDs. Understanding the gut’s role is key to protecting your horse’s overall wellbeing.

The Role of the Gut in Horse Health

A healthy gut digests fibre-rich forage, absorbs nutrients, and protects against harmful substances. Beneficial microbes in the hindgut ferment fibre to produce energy, while the gut lining selectively blocks toxins, bacteria, and undigested feed.

Gut health affects:

• Immunity

• Energy levels

• Weight maintenance

• Behaviour

• Performance

A strong gut helps horses cope with physical demands, stress, and environmental changes, supporting long-term wellbeing.

What are the Signs of a “Leaky Gut” in Horses?

Early detection prevents serious problems. Watch for:

• Digestive Upset – Loose stools, diarrhoea, inconsistent manure

• Poor Appetite – Reluctance to eat, sudden weight loss

• Behavioural Changes – Irritability, lethargy, anxiety

• Skin & Coat Issues – Dull coat, hair loss, slow-healing wounds

• Susceptibility to Illness – Frequent infections, slow recovery

• Performance Drops – Reduced energy, stamina, or training inconsistencies

Spotting these signs allows for dietary adjustments, stress management, and supportive supplements to restore gut health.

What Causes Leaky Gut in Horses?

Leaky gut develops when the gut lining weakens, letting toxins and undigested feed enter the bloodstream. Key factors include:

• Diet

• High-starch or sugary feeds disrupt the gut microbiome

• Low forage intake reduces fibre fermentation

• Sudden feed changes stress the digestive system

• Stress

• Transport, competition, or intensive training

• Routine or environmental changes

• Social stress or illness

• Environmental & Management Factors

• Limited turnout or movement

• Inconsistent feeding schedules

• Poor access to clean water or stable conditions

• Medication Use

• Long-term NSAIDs or other gut-irritating drugs

Understanding these factors helps owners reduce the risk of leaky gut.

What Can You Do if Your Horse has a “Leaky Gut?

Early action can restore gut health. Steps include:

• Adjust Diet – Increase forage, reduce starch and sugar, introduce gut-friendly feeds

• Support the Microbiome – Use probiotics, prebiotics, or herbal supplements

• Manage Stress – Minimise travel, routine changes, and overtraining

• Review Medications – Consult your vet about NSAID or gut-irritating drugs

• Ensure Hydration & Turnout – Clean water and regular movement

• Monitor Health – Track manure, appetite, coat condition, and energy levels

These measures help strengthen the gut lining and support overall wellbeing.

Treating Leaky Gut Syndrome in Horses

Treatment focuses on restoring gut integrity and supporting overall health:

• Dietary Changes – High-quality forage, reduced starch/sugar, slow feed options

• Supplements – Probiotics, prebiotics, digestive enzymes, gut-soothing herbs

• Stress Management – Minimise travel, overtraining, and routine changes

• Veterinary Care – Check for underlying issues and get targeted guidance

• Hydration & Turnout – Clean water and regular movement

Combining these approaches rebuilds a healthy gut and improves performance and wellbeing.

How to Prevent Leaky Gut: Tips for Horse Owners

Consistent care keeps your horse’s gut strong:

• Balanced Nutrition – Plenty of forage, limit starch/sugar, gradual feed changes

• Regular Exercise & Turnout – Daily movement supports digestion and health

• Stress Management – Minimise travel, routine changes, and overtraining

• Hydration – Constant access to clean, fresh water

• Routine Health Checks – Monitor weight, coat, manure, and behaviour

✅ Tip: Consider adding supportive gut supplements during stressful periods, like travel or competition, to help maintain a balanced digestive system.