Laminitis has long been regarded as a spring affliction associated with a peak in grass growth. However, this is a dangerous assumption: the condition — the second biggest cause of lameness in horses and ponies in the UK — can also emerge in the autumn or indeed throughout the year.
In equine anatomy, the laminae are the tissues that connect the coffin bone to the hoof wall, keeping it suspended within the hoof capsule. When a horse develops laminitis, the laminae weaken and fail, causing severe pain and lameness. If enough tissue breaks down, this can lead to the coffin bone rotating away from the hoof wall and eventually sinking within the hoof.
The exact cause of laminitis is still unclear but we know the condition can have multiple triggers — from the complications of an infection to insulin resistance, Cushing’s disease or even a reaction to some drugs. But one factor in particular is usually linked to laminitis: a diet that’s too rich in soluble carbohydrates.
Carb intake may easily become too high if a horse eats too much lush, rich grass, which has high levels of simple sugars, or too many grains, which contain starch that then gets turned into simple sugars during digestion.
Research has shown that too much sugar disrupts bacteria in the horse’s hindgut and can lead to high levels of insulin in the blood, both of which are associated with laminitis.
The past few months, in particular, have seen ideal growing conditions in our paddocks: warm, sunny days, cool nights and plenty of rain. The resulting growth surges can produce an excess of sugars in the grass, which, in turn, can overload the horse’s digestive system with carbohydrates and trigger laminitis.
So, how can you recognise the signs of laminitis and how do you go about protecting your horse?
In the early stages of the condition, you may just get a sense that your horse isn’t quite right. Later on, signs vary depending on the severity of laminitis, but watch out for:
• Your horse walking stiffly or being reluctant to walk or trot
• A tendency for your horse to stand with its front legs stretched forward, while leaning backward, to ease the weight off his feet
• Your horse shifting his weight from foot to foot
• An obvious pulse where your horse’s digital artery runs over the fetlock
• Foot soreness or lameness, with a particular difficulty to turn in a circle
• Unwillingness or, in severe cases, inability to move. Your horse may be panting, sweating and leaning back on his heels, trying to take his weight off his feet. In the worst cases, he will lie down and be unable to stand — this can be confused with colic.
If your horse suffers from chronic laminitis, his hooves may change, showing dropped soles, visible, diverging growth rings around the hoof wall and wider than normal white lines.
It is incorrect to think that all cases of laminitis are caused by poor horse management, or that laminitis only occurs in overweight ponies. This disease does not discriminate and can affect any horse, even top-flight racehorses such as the Triple-Crown winner Secretariat and the Kentucky Derby winner Barbaro.
There are some general rules of thumb, though. Animals that are fit are generally less susceptible to laminitis, and those that are prone to it should be kept well exercised.
Feed your horse according to the work he does. A laminitis-prone horse or pony should always follow a diet that’s high in fibre and low in sugars and starch. Choose hay that has low nutritional value and Laminitis-Trust approved feed, and consider a grazing muzzle or strip grazing to restrict grass intake.
Don’t allow your horse to become fat but also remember that horses have evolved to be trickle feeders, so it is best to provide feed little and often. Never starve a horse or a pony as this could lead to a very serious condition called hyperlipidaemia.
If you suspect laminitis, it is vital to contact your vet immediately. The sooner you act, the less likely it is your horse will suffer serious permanent damage. Put your horse in a stable that has a deep bed made of clean shavings, provide plenty of water and don’t make him walk or exercise. If your horse is in a field that’s far away from the stables, put him in a trailer rather than make him walk back.
Your vet will then provide the appropriate medicines, fit frog supports, and treat any underlying problem that may be causing the laminitis. You’ll also need to ask and follow the vet’s advice for feeding and turnout.