Weather patterns that bring plenty of rain followed by warm sunshine create ideal grass-growing conditions.
While your paddocks may look fantastic, these conditions also increase the risk of one of the most devastating diseases affecting horses— pasture associated laminitis.
If your horse or pony has Equine Metabolic Syndrome (EMS), Insulin Dysregulation (ID) or PPID (Cushing’s disease), spring and autumn are times to be particularly vigilant.
What Is Laminitis?
Laminitis is a disease affecting the laminae, the specialised tissues that suspend the coffin bone within the hoof capsule.
These tiny structures act like thousands of Velcro-like attachments, holding the bone securely in place.
When the laminae become damaged, they weaken and may no longer support the coffin bone properly.
In severe cases the coffin bone can rotate or sink within the hoof, causing extreme pain and permanent damage.
Why Does Fresh Grass Increase the Risk?
Young, rapidly growing pasture often contains higher concentrations of water-soluble carbohydrates, including sugars.
When horses prone to insulin dysregulation consume large amounts of these sugars, blood glucose rises after digestion.
The pancreas responds by releasing insulin.
Healthy horses regulate this process efficiently.
However, horses with insulin dysregulation produce excessive amounts of insulin, and these elevated insulin concentrations can persist long after eating.
This condition is known as hyperinsulinaemia.
Research now shows that prolonged elevations in insulin are the primary trigger for most cases of endocrinopathic laminitis.
Does Hindgut Acidosis Cause Every Case?
Not necessarily.
There are two major forms of laminitis.
Endocrinopathic Laminitis
This is by far the most common form seen today and is associated with:
- Equine Metabolic Syndrome (EMS)
- Insulin Dysregulation (ID)
- PPID (Cushing’s disease)
In these horses, prolonged elevations in insulin damage the laminae.
Sepsis-Associated Laminitis
This form occurs following conditions such as:
- Grain overload
- Severe colitis
- Retained placenta
- Systemic illness
Here, large amounts of starch escape into the hindgut, disturbing the microbial population.
Rapid fermentation produces lactic acid, beneficial bacteria die, toxins are released and widespread inflammation develops, which can ultimately damage the laminae.
Although both forms result in laminitis, the underlying causes are different, which is why correct diagnosis is so important.
How Does High Insulin Damage the Hoof?
Scientists are still working to fully understand the process.
Current evidence suggests that prolonged elevations in insulin alter the function of the laminar cells themselves rather than simply reducing blood flow.
These changes weaken the attachment between the hoof wall and the coffin bone, eventually allowing structural failure if the condition is not controlled.
Signs of Laminitis
Early recognition is critical.
Watch for:
- Reluctance to walk
- Stiff or pottery gait
- Heat in the feet
- Increased digital pulse
- Standing with front feet stretched forward
- Frequent weight shifting
- Lying down more than usual
- Reluctance to turn
- Pain when walking on hard ground
If you suspect laminitis, contact your veterinarian immediately.
Early treatment significantly improves the outcome.
Preventing Laminitis
Nutrition plays one of the biggest roles in prevention.
Restrict High-Risk Grazing
During periods of rapid pasture growth:
- Limit grazing time.
- Use a grazing muzzle if appropriate.
- Graze during lower-risk times (very early morning) when advised by your nutritionist.
- Consider using a sacrifice paddock where necessary.
Feed Plenty of Fibre
Fibre should always remain the foundation of the horse’s diet.
Provide:
- Good-quality low sugar hay
- Low-sugar chaff
- Suitable high-fibre feeds where required
Maintaining fibre intake supports the hindgut microbiome and helps reduce reliance on high-sugar pasture.
Manage Body Weight
Overweight horses are significantly more likely to develop insulin dysregulation.
Maintaining an appropriate body condition score is one of the most effective ways to reduce laminitis risk.
Choose Low Sugar and Low Starch Feeds
Avoid unnecessary grain and feeds high in sugar or starch.
Where possible, base the diet on forage analysis and select feeds appropriate for horses with metabolic disease.
Encourage Regular Exercise
Once approved by your veterinarian, regular exercise improves insulin sensitivity and helps maintain a healthy body weight.
What About Supplements and Herbs?
Many supplements and herbal products are marketed for horses prone to laminitis.
Some ingredients may support general health or provide antioxidant properties, but no supplement or herb can replace good management.
The foundations of prevention remain:
- Appropriate veterinary care
- Correct diagnosis
- Controlled grazing
- Weight management
- A balanced low-sugar, low-starch diet
- Correct hoof care
If you choose to use herbal products, they should be prescribed by a suitably qualified equine herbal practitioner and used alongside—not instead of—evidence-based veterinary treatment.
The Bottom Line
Laminitis is not simply a “grass problem.”
It is a complex disease that, in most horses today, is driven by hormonal changes associated with insulin dysregulation.
The good news is that many cases can be prevented.
Understanding your horse’s risk, carefully managing pasture, maintaining a healthy body condition and feeding a balanced diet based on plenty of fibre are the best defences against this painful disease.
As someone who has managed horses recovering from laminitis, I can say with confidence that prevention is always easier than rehabilitation.
Nutrition is the science of prevention.
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