Feeding Horses with Laminitis: What Actually Works and What to Avoid
By Dr Duncan Houston
If your horse has laminitis or is at risk, feeding decisions are one of the most important factors in whether the condition stabilises or worsens.
Many cases of laminitis are not caused by grain overload, but by pasture. Horses that appear to be on a “natural” grass diet are often exposed to high sugar levels that trigger the condition.
This is where most management plans fail. The diet looks normal, but the metabolic impact is not.
Quick Answer
Most laminitis cases are linked to high sugar intake from pasture. Horses at risk should be managed on low-NSC forage, with restricted or controlled grazing, weight management, and careful monitoring of insulin response. Simply limiting grazing time is often not enough.
Why Pasture Causes Laminitis
Grass contains non-structural carbohydrates, mainly sugars and starches.
When a horse consumes high levels:
-
blood sugar rises
-
insulin levels increase
-
blood flow and cellular function in the hoof are disrupted
This leads to inflammation and weakening of the laminae.
In practice, laminitis is often an insulin-driven disease, not just a dietary one.
Which Horses Are Most at Risk
Certain horses are far more sensitive to pasture sugars.
Higher-risk groups include:
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easy keepers
-
overweight horses or ponies
-
horses with cresty necks or fat pads
-
horses with equine metabolic syndrome
-
older horses with PPID
These horses do not need large amounts of sugar to trigger a problem.
Why Grass Is Not Consistent
One of the biggest misconceptions is that grass is always safe.
Sugar levels in pasture change based on:
-
time of day
-
weather
-
season
-
plant stress
For example:
-
sugar levels rise throughout the day
-
late afternoon and evening often have the highest levels
-
stressed grass, such as during drought or frost, can contain higher sugar
This is why laminitis can appear suddenly even when management has not changed.
Why Time-Restricted Grazing Often Fails
Many owners try limiting turnout to a few hours per day.
The problem is:
-
horses compensate by eating faster
-
total sugar intake may stay the same or increase
Short periods of unrestricted grazing can still deliver a high sugar load.
The only relatively safer window is early morning, when sugar levels are lowest, but even this is not risk-free.
How Serious Is This?
Low Risk
-
normal weight
-
no history of laminitis
-
controlled pasture exposure
What this means: routine monitoring is sufficient
Moderate Risk
-
overweight
-
early metabolic changes
-
mild laminitis history
What this means: diet must be actively controlled
High Risk
-
confirmed laminitis
-
insulin dysregulation
-
recurring episodes
What this means: strict dietary management is essential
Critical
-
active laminitis episode
-
significant pain or hoof instability
What this means: immediate removal from pasture and full dietary control
What To Feed Instead
The foundation of feeding a laminitis-prone horse is low sugar forage.
Low-NSC Hay
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ideally tested and below 10 percent NSC
-
forms the base of the diet
Soaked Hay
-
soaking can reduce sugar content
-
useful when low-NSC hay is not available
Avoid
-
grain
-
sweet feeds
-
molasses
-
high-sugar treats
In practice, removing hidden sugars is one of the most effective steps.
Key Management Strategies That Actually Work
Remove or Strictly Control Pasture Access
Dry lot systems are often the safest option for high-risk horses.
Use Grazing Muzzles
These can significantly reduce intake while allowing movement and turnout.
Feed Smaller, More Frequent Meals
This helps reduce insulin spikes and stabilise metabolism.
Monitor Body Condition Closely
Target a moderate body condition.
Weight control is one of the most powerful tools in preventing laminitis.
Time Grazing Carefully
If grazing is allowed:
-
early morning is the lowest-risk period
-
avoid afternoon and evening turnout
Even then, caution is required.
Understanding Insulin Resistance
In horses with metabolic issues:
-
the body produces more insulin than normal
-
tissues respond poorly to insulin
-
high insulin levels damage the laminae
This is why laminitis can occur even without obvious overfeeding.
Testing may include:
-
fasting insulin levels
-
oral sugar testing
Identifying this early changes management significantly.
What To Do Right Now
If your horse is at risk or has had laminitis:
-
remove access to lush pasture immediately
-
switch to low-NSC forage
-
avoid all high-sugar feeds
-
assess body condition honestly
-
involve your vet if there are any signs of foot soreness
If there are signs of active laminitis, treat this as urgent and act immediately.
When Is This an Emergency?
Treat as urgent if:
-
your horse becomes foot sore
-
shifting weight or reluctance to move develops
-
digital pulses increase
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heat is felt in the hooves
These are early signs that require immediate action.
Common Mistakes
-
assuming grass is always safe
-
relying only on time-restricted grazing
-
underestimating sugar content in pasture
-
ignoring weight gain
-
delaying action after early signs
In practice, these are the exact reasons laminitis continues to occur.
Long-Term Prevention
Successful management focuses on:
-
consistent diet control
-
maintaining appropriate weight
-
monitoring pasture conditions
-
managing underlying metabolic disease
Laminitis is rarely random. It is usually predictable once you understand the risk factors.
Frequently Asked Questions
Can laminitis-prone horses ever graze safely?
Sometimes, but only under strict control. Many require permanent restriction during high-risk periods.
Is hay always safe?
Only if sugar levels are low. Testing or soaking may be needed.
Is night turnout safer?
Sometimes, but sugar levels can still rise depending on conditions. Early morning is generally safer.
Do grazing muzzles really help?
Yes. They can significantly reduce intake and are one of the most practical tools available.
Can weight loss reverse risk?
It can significantly reduce risk, especially in metabolic horses.
Final Thoughts
Feeding a horse with laminitis is not just about removing grain. It is about understanding how sugar intake affects the body and the hoof.
The key decisions are:
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how much sugar is being consumed
-
when it is being consumed
-
how the horse’s body is responding
When these are controlled properly, laminitis can often be stabilised and prevented from recurring.
If you are unsure whether your horse’s diet is truly safe or want help building a practical feeding plan, ASK A VET™ can guide you through the next steps with clear, case-specific advice tailored to your horse.
This article is general veterinary education and does not diagnose or treat an individual animal. Always confirm medication names, doses and interactions with the veterinarian who knows your pet.
If your animal is struggling to breathe, collapsed, bleeding heavily, seizing, or has eaten something toxic, contact your vet or the nearest emergency clinic now.
Animal Poisons Helpline (AU) 1300 869 738 · Animal Poisons Helpline (NZ) 0800 869 738 · ASPCA Animal Poison Control (US) (888) 426-4435
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Ask A Vet articles are written by Dr Duncan Houston BVSc, a practising veterinarian, unless another author is named in the byline.




