Our particularly wet and warm Summer and the sudden onset of Autumnal mornings has caused a sharp spike in the sugars in the grass. The result? A bout of Autumn growth and with it, an increase in the risk of laminitis and Equine Metabolic Syndrome.

While the grass may look as if it no longer has any goodness left, this in fact isn’t the case. Our fields are full of unmeasurable levels of Water Soluble Carbohydrates (WSCs). As the nighttime temperatures drop, and warm sunny days follow, the WSCs in the grass aren’t being utilised. When they’re produced throughout the course of the warm day, they’re generally used up in the grass growth overnight. However as soon as temperatures start to drop, this isn’t possible.

Weight related issues such as Laminitis and Equine Metabolic Syndrome (EMS) are synonymous with Spring and Autumn grass growth, so prevention here is key. The prevalence of EMS in the equine industry is of high importance due to its association with Laminitis. The majority of Laminitic cases are thought to be secondary to EMS. Animals with high levels of Insulin resistance are more likely to develop EMS so evaluating this likelihood could actually prevent your horse or pony developing this issue.

While there are not as clear signs with EMS as there is with diseases such as Colic and Equine Gastic Ulceration, symptoms do become more apparent as the disease progresses. The most significant and in fact easy to acknowledge symptom is the prevalence of regional adiposity which are particularly common in the crest and tailhead regions. A useful managerial tool for owners is the introduction of a neck crest scoring system, which has been designed to distinguish horses that have developed regional rather than generalised obesity.

While Laminitis is often a disease associated with pony breeds, EMS has a significant presence in Thoroughbreds, Warmbloods and Arabians as well as the smaller breeds such as Welsh, Dartmoor and Exmoor Ponies. A study by Treiber (2006) showed that Welsh and Dartmoor ponies have a 10-fold higher risk of developing Laminitis than noninsulin-resistant ponies.

Once a horse or pony has developed EMS or Laminitis, their chances of contracting it again are increased. Horses that have had EMS are also more likely to develop Pituitary Pars Intermedia Dysfunction (PPID - also known as Equine Cushings Disease) so reducing that initial risk is essential.


Regular exercising not only wards off obesity but can improve insulin sensitivity in horses and ponies. Insulin sensitivity decreases as body fat mass increases so insulin sensitivity can be corrected through the treatment or prevention of obesity.

Dietary Plan

Feeding mature hay is beneficial because of its low non-structural carbohydrate (NSC) content. Newer grass, haylage and silage should be avoided at these times. If your horse is at a particularly high risk or you’re worried, you should seek a nutritional analysis of your grass and forage, but please do bare in mind that every bale, and every patch of grass varies, so a true representation is hard to quantify. For further information, speak to a qualified nutritionist who can help to create a bespoke plan for your horse or pony.