Supporting Gastrointestinal Tract Health in the Horse - Emma Hardy, PhD

Maintaining the health of the equine digestive system can be a challenge for veterinary professionals and their clients, particularly given the stress of modern care, feeding and performance.


Whilst it is well accepted that specific nutrition, feeding and management routines are necessary to meet the high demands placed on the performance horse, these are frequently a significant departure from how the digestive tract has evolved to function. As a result, our horses are at risk of a wide range of health issues.


Evolution vs. Modern lifestyle

A horse at grass will nomadically graze for up to 19 hours per day. This trickle intake of fibre is crucial for maintaining the balance between continuous gastric acid production and the buffering capacity of saliva. When normal intake becomes restricted - perhaps through stabling or training - the integrity of the horse’s gastric mucosa becomes vulnerable to the effects of gastric acid, and inflammation and lesions can develop. Dietary forage also exerts a greater buffering effect than concentrates, both due to its properties and increased chewing time.

Maximising forage intake and supporting the natural defensive properties of the gastric mucosa are ideal strategies for the stabled horse in training. Pharmacological suppression of gastric acid production, though common, reduces the activity of several digestive enzymes which are activated in the presence of the acid. This can lead to a diminished ability for the horse to fully digest concentrates. Unfortunately, the negative connotations of gastric acid have been all too well publicised with little regard to its positive effects in terms of both digestion and immunity.

Whole Tract Health

Although much focus has been placed on gastric health, particularly in the performance horse, an imbalance at the front of the GI tract will inevitably influence things that happen further downstream. This supports the view that the equine gastrointestinal tract should be approached as an entire system, and not just as a single set of components – and certainly not only in terms of the stomach.

Enzymatic digestion of proteins, fats, sugars and starch occur within the small intestine, and requires sufficient surface contact time to be effective. However, transit time of digesta is very much dependant on feed size and type. Poor digestion within the small intestine will lead to escape of these nutrients into the large intestine where rapid fermentation causes serious dysbiosis. The microbiota of the large intestine exists in a delicate state and is easily unbalanced by events which alter the pH and bacterial populations. This all too often provides the source of numerous GI tract disorders, both localised, such as ulceration and colitis, and systemic, such as endotoxemia and laminitis.  

Internal problems can cause external problems

Any significant gastrointestinal disturbance will adversely affect performance and overall well-being of the horse. Even though the actual influence can be very hard to quantify, there are plentiful reports of horses that have performed poorly, behave badly, and/or show behavioural neuroses who then go on to be diagnosed with significant gastrointestinal issues. Overt signs tend to be associated with some degree of discomfort emanating from the abdomen and flanks.  These may manifest as a general deterioration in performance, attitude to work, and temperament both on the ground and under saddle, as well as more typical signs linked to poor digestion and digestive health such as loss of condition, weight and diarrhoea.

Early, rapid detection and effective treatment is crucial in obtaining rapid resolution of the issues. Further, long term preventive strategies are ultimately key for improved overall health and better performance.

Prevention is key

Unfortunately for the riding horse, a low stress lifestyle and a high fibre trickle fed diet is often difficult to implement and invariably not conducive to obtaining peak performance. Taking steps to offset the digestive health risks which can be increased under these conditions is paramount. This may be accomplished through optimising management routines, making sensible dietary changes or adding specific nutrients to the diet to support and enhance GI tract health and functioning. 

SUCCEED™ Digestive Conditioning Program™ is a once-daily supplement program, developed to aid normal digestion, absorption and total gastrointestinal tract health. It has been particularly beneficial for horses faced with nutritionally or environmentally challenging circumstances.

SUCCEED supports Gastrointestinal Tract health

The primary ingredients in SUCCEED are Polar lipids and Beta glucan, derived from Oat Oil and Oat Flour, respectively.

Polar lipids play an important role in cellular membranes, helping to maintain tight junctions between the epithelial cells present in gastrointestinal mucosa. Tight junctions optimise the natural defensive mechanisms within the gut lining to protect against gastric acid, pathogens and toxins, which helps to reduce the risk of inflammation and development of lesions. Oat oil is also naturally high in the anti-oxidant Vitamin E. Free radicals are formed in response to exercise and have been associated with muscle fatigue; however, vitamin E scavenges these products of oxidative stress and helps to protect against damage free radicals can exert on cellular membranes.  The bioavailability of water- and fat-soluble molecules is enhanced by using polar lipids as a carrier, improving availability of several vitamins by up to 500%. This helps to maximise uptake of the ingredients in SUCCEED into the vascular system and tissues.

Beta-glucan is a soluble fibre which, when fed alongside concentrates, creates a hydrogel that helps to moderate the transit of starches through the gastrointestinal tract. This ensures a more complete digestion within the small intestine, thus minimising risk of fermentation within the large intestine. It has been shown that beta-glucan can reduce post prandial glycaemic peaks by up to 50%, which can have positive effects on behaviour, especially in horses fed high starch diets to meet energy demands. Beta-glucan has a highly stimulatory effect on phagocytosis and macrophages to boost immunity and counteract pathogenic microbes and is also a highly efficient mycotoxin adsorbent. This helps to minimise, decontaminate and thus control the toxicity of mycotoxins produced from ubiquitous fungi and moulds.

SUCCEED also contains the amino acids L-Glutamine and Threonine which are well documented as beneficial to gastrointestinal tract health. During times of stress and intensive training, L-Glutamine can become depleted leading to increased intestinal permeability and atrophy of the intestinal villi. Necrosis, poor nutrient absorption and inflammation/ulceration can result so dietary glutamine can help avoid these issues whilst also providing a fuel source for intestinal epithelial cells. Threonine is an important component of mucin; proteins which are produced by intestinal goblet cells scattered along the intestinal villi to enhance the gut barrier function.  A healthy mucus gel layer protects the gut against digestive enzymes and physical damage by digesta. Intestinal inflammation increases threonine uptake by the gut in order to synthesise more mucin, and as synthesis is sensitive to dietary threonine supply, the addition of this amino acid is beneficial in promoting optimal health of the tract lining.

The yeast product, Mannan oligosaccharide, is extracted from the outer cell wall of Saccharomyces cerevisiae. Its primary role in the SUCCEED formulation is the competitive blocking of bacterial lectins. Bacterial lectins have an affinity to bind with glycoproteins attached to the membrane of intestinal enterocytes; the first stage of infection. The mannan mimics these glycoproteins, providing an alternative attachment site and essentially “tricks” the pathogenic bacteria into binding with it instead. This helps to block colonisation of pathogenic bacteria organisms such as Clostridium, E.coli and salmonella by adsorbing and safely removing them. The resulting effect is a positive modulation of gut microflora and reduced risk of infection.


The nutrients in SUCCEED equip the horse to obtain and maintain digestive health when faced with conditions which are contrary to its optimal functioning. By directly supporting the structure and functioning of the gut, whilst also facilitating nutrient absorption, the horse can cope and thrive even in the face of modern feed, feeding and management routines.