That Gut Feeling: How stress shapes your horse’s health from the inside out
Good digestive health is now recognised as the foundation of equine wellbeing and performance. When the gut is healthy, everything else falls into place – from energy levels and condition to behaviour and resilience.
Inside the gut lives a vast community of microbes known collectively as the gut microbiome. Think of it as an internal ecosystem: when it is in balance, it powers digestion, supports immunity and keeps your horse feeling and performing at its best. But when that balance is disturbed, known as dysbiosis, the horse’s ‘internal engine’ starts to misfire. This can have knock-on effects throughout the body.
One of the biggest triggers for this imbalance is stress. Whether physical, mental or metabolic (the type linked to nutrition and energy use), stress has an impact on the gut and, over time, the horse.
Not all stress looks the same
As prey animals, horses are hardwired to hide discomfort or vulnerability. That means stress isn’t always easy to spot, especially when it’s mental or metabolic rather than physical. And, just like people, every horse responds differently – what one takes in its stride can rattle another.
Stress can creep in through everyday changes - new routines, the environment, transport, training intensity, social dynamics or illness. Some stress is natural and even helpful - it allows horses to adapt to new situations. But when small stressors keep repeating or build up over time, the body’s stress response can get ‘stuck on’.
This lingering, low-level stress keeps hormones like cortisol elevated, which can start to affect digestion, behaviour and health. Larger changes - such as moving yards, a new training regime, frequent competition travel or the loss of a companion - can also overwhelm a horse’s coping system and lead to chronic stress.
Chronic stress doesn’t just affect mood or behaviour. It changes biology – disrupting the gut microbiome and triggering a chain reaction that impacts the whole body.
Finding the right balance is key and what works for one horse might not work for another.
Recognising the signs of stress
Many stressors are part of everyday life for horses - and often we don’t realise their effects until subtle signs appear. Look out for:
- Changes in behaviour, mood or appetite
- Reduced performance or slower recovery
- Weight loss, dull coat or loss of ‘spark’
- Loose or smelly manure
- Stereotypies (weaving, cribbing, box walking)
- Sensitivity during grooming or tacking up
- Weakened immune function
Common triggers include:
- Lack of forage or irregular feeding
- Isolation or restricted turnout
- Sudden changes in diet, environment or companions
- Frequent travel or competition schedules
- Pain or discomfort
- Over- or under-feeding high-energy diets
- Weaning, seasonal changes or yard moves
- New riders or owners
- Disease
No two horses will respond in exactly the same way - what unsettles one may barely affect another. Understanding your horse’s normal behaviour and routine is the best way to spot when something’s not right.
How stress affects the gut – and vice versa
When stress disrupts the microbiome, digestion becomes less efficient and inflammation can increase. This may contribute to issues such as:
- Ulcers (squamous, glandular, pyloric and colonic)
- Colic
- Leaky gut (reduced gut barrier function)
- Systemic acidosis
- Laminitis
- Weakened immunity
- Poor performance and recovery
Science now shows that the gut and the brain are closely connected - a two-way communication system often called the gut–brain axis. When the gut is unhappy, it can send signals that influence mood, energy and behaviour. Likewise, when a horse is mentally or physically stressed, the gut feels the effects.
Supporting a healthy balance
Recognising the early signs of stress - and supporting the gut before issues take hold - can help horses stay resilient, recover faster and perform at their best. Good management practices - consistent routines, adequate forage, social contact, and nutritional support for the hindgut - all play a part in protecting both mental and digestive health.
Adding targeted gut support can also strengthen the foundations. For example, feeding Actisaf® Sc47 live yeast helps to stabilise the hind gut microbiome and improve fibre digestion - playing a role in improved performance, well-being and hindgut function.
By understanding how stress and the gut interact, we can manage horses more holistically – building calm animals and supporting wellbeing from the inside out.
Learn more about the Gut-Brain Axis here.
