Natural Horse World

Why Do I need to Know About Grass?

Grass is one of those things we take for granted if we have it, and wish we had it if we don’t, especially in times of drought.
If we have a paddock full of lush grass we think our horses are lucky.
But did you know grass can be just as harmful for your horse as much as it’s helpful in providing nutrients?
Recent research by people such as Kathryn Watts from Colorado, has revealed that grass can cause our horse to show slight lameness, shortness of stride, tie-up (azoturia) after exercise, contribute to ‘Cushing’s Syndrome’ and hoof abcesses, and of course, cause laminitis and founder.

Many of our horses probably die early or are ‘put down’ because of the problems they develop from eating grass either at the wrong time of the day or year, or the wrong type of grass. In fact it has been proven that animals who have their intake of calories restricted by 30-40% live a lot longer.
In other words, people love their horses so much they feed them ‘to death’.
One of the most common reasons for horses to be retired or euthanaised is irreparable lameness and it’s estimated that 80% of horses in the world show some form of clinical lameness.

Most of these lamenesses originate in the lower 1/3rd of the leg with a very high percentage in the hoof from ‘diseases’ such as navicular and laminitis, abcesses and seedy toe (or white line disease).
While some stresses to the hoof such as navicular are related more to the hoof form being out of shape due to shoeing and bad/neglectful trimming, most others can be controlled through diet. Laminitis, seedy toe and the abcesses that result from the hoof trying to rid itself of toxins can all be fixed with a careful diet that controls the damage done to the laminae inside the hoof.

Damage to the sensitive laminae cause them to seperate and destroy the bond between the inner hoof structures and the outer hoof wall. When this bond is broken, lameness occurs as it is a bit like us tearing a fingernail from the skin below – it gets pretty sensitive until it can grow more tissue and heal.
As the torn laminae grow down with the hoof wall towards the ground, the dead tissue spaces (seperation of the hoof wall) allows bacteria to enter and then you have seedy toe or white line disease.

Abcesses commonly occur to rid the hoof of the dead tissue from within, especially when the horse has suffered laminitis and a large amount of toxins must be removed. When the blood flow that carries these toxins away from the hoof is compromised by shoeing or lack of movement such as when the horse is footsore and cannot move much, then an abcess is the only way to force the toxins out.
So what has this all got to do with grass I hear you say?

Well, grass manufactures sugars in the form of non-structural carbohydrates (NSC) and when these sugars overload the horse’s hind gut, in simple terms, it causes the gut to release toxins into the blood which then flows to the hooves and effects the laminae as described above.
So, if we know how to limit the NSC to a safe level, then we can save our horse from a lot of suffering and save ourselves from a lot of vet bills.
Most people already realise that a horse who gets into the grain bin and gorges, will founder, as do ponies on rich grass in spring time.
This is the extreme end of the scale, but if we are more aware of what is happening to our horse’s hooves, they will show us that minor episodes of laminitis (a major episode is called founder) are happening in response to the grass or concentrate feed our horse is eating.

Commonly, horses become sensitive in their hooves when they have a minor laminitic attack. You may notice your horse is reluctant to move forward, takes short steps or ‘plays up’ when asked to circle. They will be footsore on gravel or rocky surfaces, always looking for the edge where the grass grows or the going is softer. That’s what makes most horse owners reach for the phone to call their farrier to put shoes on, when in reality they should be restricting grass intake and buying a set of boots to help protect the hooves in a healthy way when they want to ride.
Some footsoreness can be due to lack of good hoof form ie; flat soles therefore sensitive, but this is also just another symptom of mild laminitis. The soles appear to have dropped but what’s really happening is the hoof wall is seperating and growing forward from the coffin bone because of a weak laminar attatchment, causing the sole and coffin bone to become weight bearing and therefore sensitive to direct pressure.

As you can see, the root cause of many hoof problems and therefore soundness, is the damage to the laminae which is like velcro – it holds the hoof together.
The cause of damage to the laminae is commonly the toxins released from the horse’s hind gut in response to an overload of sugar.
The sugar overload comes from a high level of sugar or NSC in the grasses the horse eats (even in the dried grass – hay) which is the reason we need to know more about grass.
We need to know when it is safe to allow the horse to eat grass or when the grass has a low level of NSC’s.
We need to know what types of grasses have lower levels of NSC and which ones have a higher amount – usually those developed for the beef and dairy industries to grow lots of muscle, fat and milk.
We need to know what affects the NSC content of grasses – like the weather, fertilisers used, when it is cut for hay etc.

For more information on grasses go to

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