When a horse is exercising heavily, especially in the heat, they will of course sweat a lot and often drink less, causing dehydration and electrolyte abnormalities, which in turn effects the ability of the gut to function well.
Water is one of the most important elements of a healthy digestive system. From the production of the saliva, digestive secretions and enzymes to the fermentation and absorption of the food in the gut. Being adequately hydrated is also extremely important for the smooth passage of food through the digestive tract.
When the horse is dehydrated the sodium concentration in the blood increases, this leads to movement of water from the digestive system into the blood to maintain balance which is where the disruption in intestinal function starts.
Excessive sweat losses in hot weather and during exercise can be compounded by an increase in the quantity of hay in the diet when travelling and at competitions. Hay is as little as 10% water whereas grass is typically 70%, just the switch to a dry diet significantly reduces the daily water intake.
Even just traveling in a float on a hot day can lead to excessive sweat losses! Then you add the stress of being away from home, changes in feed and water, exercise and less time to actually eat and you can run into problems quickly!
Intense exercise also increases the body’s core temperature, which can affect the microorganisms in the gut leading to less efficient fermentation, feed utilisation and absorption.
Intense or prolonged exercise, especially in the heat, can also lead to the gut becoming more permeable with bacterial products leaking into the bloodstream, this is called endotoxemia and can make the horse very sick, the balance between the good and bad gut bacterial populations can also become imbalanced.
Some key elements to keep in mind when exercising, travelling and competing especially on hot days include:
💦 Make sure the horse has free access to quality hay and water at all times
💦 Feed extra salt on hot days to encourage drinking and help balance electrolyte losses in sweat
💦 Boost gut health by feeding probiotics to increase the number and variety of microorganisms available for efficient fibre fermentation
💦 Feed hi fibre feeds such as beet pulp, maxi-soy and psyllium husk as a source of easily fermentable fibre prebiotics
💦 Make sure you condition the horse properly for the work required
💦 GI soothing herbs such as aloe vera powder, marshmallow, liquorice and slippery elm can help the digestive tract cope with challenges
There are many challenges facing our domesticated horses, especially those undergoing intense or regular sustained exercise, travel and competition. But with a few good management practices and attention to dietary intake, we can mitigate some of the risks to the digestive system and help to create more health resilience!
The horse’s microbiome consists of the microorganisms, bacteria, fungi along with their interactions and functions in the horse’s digestive system.