High severity

Equine Metabolic Syndrome (EMS)

EMS is a hormonal disorder characterised by insulin dysregulation, regional fat deposits, and a high risk of laminitis. It is most common in 'easy keepers' and certain breeds (ponies, Morgans, Arabians).

Symptoms to watch for

Cresty neck and fat pads above the eyes, near the tail head, or in the sheath

Generalised obesity despite restricted intake

History of laminitis episodes

Lethargy and exercise intolerance

Abnormal oestrus cycles in mares

Excessive thirst and urination in advanced cases

Common causes

Genetic predisposition (ponies, Iberian breeds, Morgans, Arabians)
Chronic over-feeding of energy-dense feeds
Insufficient exercise
High-sugar pasture and treats

Prevention

Test insulin and glucose levels in at-risk horses annually
Feed low-NSC hay (under 10% sugar + starch); soak hay if needed
Eliminate grain, sweet feeds, apples, carrots, and treats
Use a grazing muzzle on pasture or restrict to a dry lot
Maintain a structured exercise program (5–6 days per week)
Aim for body condition score 4–5 of 9

What to do

1
Have a vet confirm diagnosis with a resting insulin and oral sugar test.
2
Implement a strict diet: forage-only, hay tested below 10% NSC.
3
Begin a daily exercise program suitable for the horse's soundness.
4
Discuss medication (levothyroxine, metformin) with your vet for severe cases.
5
Re-test insulin every 3–6 months to monitor progress.
6
Coordinate with your farrier on preventive hoof care.

When to call the vet

Pick up the phone if…

Schedule a vet visit if you notice cresty neck, regional fat pads, or any episode of foot soreness. Call immediately if the horse shows signs of laminitis (digital pulse, reluctance to walk, sawhorse stance).

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Educational content only. Not a substitute for veterinary advice.