Laminitis guide: Part 1 - causes, prevention and treatment

Most horse owners have heard of laminitis, and those who have had experience of it know just how devastating a disease it can be. So, what is it? Laminitis is an inflammation and weakening of the many digital lamellae that joins the pedal bone within the hoof capsule to the hoof wall. These lamellae carry the whole body weight of the horse during standing rest, and far more during exercise.    

Horses with laminitis are often very lame, and this is because the inflamed lamellae are under constant load, and this load is increased during movement. In severe cases, laminitis can cause the pedal bone to detach from the hoof wall and rotate or sink towards the horse’s sole. In very rare cases, the pedal bone can lose all the laminar support and push through the sole of the hoof. In these situations, euthanasia is likely to be the only outcome. 

Although we cannot fully imagine the pain associated with laminitis, I often try to explain the dynamics to my clients. Imagine that you have a sore nail, perhaps after being trapped in a door - this is the inflammation, the laminitis. Then imagine that you apply pressure to the underside of the tip of the nail, as if you were trying to pull this gently away from the finger. Now imagine doing this on both your hands and feet, 24 hours a day! This is what the horse has to live with during a spell of laminitis!
 
Laminitis is often seen in spring and summer but it can strike at any time of the year. It may occur as a single acute episode or, more commonly, as repeated bouts over a prolonged period. There is no ultimate treatment which can remove the risk of laminitis but we now know far more about laminitis risk factors and this means that with the right diagnostics and management, sometimes combined with treatment, we can greatly reduce the risk and occurrence of laminitis. Therefore, if a horse has had laminitis or is considered to be at risk of developing laminitis, then lifelong preventative management is needed. 

Symptoms

It’s really important to acknowledge the signs of clinical laminitis early as this increases the chance of recovery.  Some of the signs to look out for include:

• Choosing to walk and stand on softer ground
• Slowing down with a ‘pottery’ gait
• Laying down more than usual
• Lameness or stilted gait that is exaggerated by turning on a hard surface
• Alternate lifting of feet and shifting of weight when standing
  Excessive heat in the feet
• A strong or bounding digital pulse
• More severe signs of pain, such as reluctance to move, facial tension or a lack of interest in the surroundings
• Leaning back on the hind limbs with front limbs placed in front of the body
• General stiffness

If you spot any one of these symptoms, it’s vital that you call your vet immediately. As a first aid you can restrict your horse to a small stable size area with a very soft surface as this helps reduce the laminar strain and pain, as well as the risk of further damage. This would ideally be a stable with a deep layer of shavings but part of a sand school or a little fenced off area in the paddock is also better than access to the whole paddock. If you have any concerns, the Agria app provides a free video call service where you can speak with an equine vet. 

Causes

Any horse or pony can develop laminitis, but some are more susceptible than others. Up to 90% of laminitic cases are thought to be linked to underlying endocrine disorders, and excess weight can also increase the risk of laminitis developing. It is therefore important to identify those horses that are at higher risk due to such underlying conditions so they can be managed appropriately.

Causes of Laminitis include:

• Predisposing conditions such as equine metabolic syndrome (EMS) or pituitary pars intermedia dysfunction (PPID, aka Cushing’s Disease)
• Sepsis or systemic inflammatory response syndrome (SIRS) (sepsis-related laminitis)
• Intake of grass with high sugar content
• Excessive grain intake
• Supporting limb compensatory weight bearing due to injury of the opposite limb
• Excessive work on hard surfaces 

Laminitis prevention and management

There is no treatment which can remove the risk of laminitis but we now know far more about laminitis risk factors and this means that with the right diagnostics, regular foot trimming and good management, sometimes combined with medical treatment, we can greatly reduce the risk and occurrence of laminitis. Therefore, if a horse has had laminitis or is considered to be at risk of developing laminitis, then lifelong preventative management is needed. 

There are ways to reduce the risk of laminitis and these include:

• Blood tests - blood tests to check for underlying disorders such as EMS and PPID offer us a simple and effective way to identify those horses that are at higher risk of developing laminitis. I recommend that horses with a history of laminitis and horses that show signs of EMS or PPID are tested for underlying endocrine disorders as this will enable owners to manage these horses in a preventative way.  Your vet will be able to advise which diagnostics are best for your horse. 
• Medical treatment - this can often help the recovery from laminitis and some medicines can reduce the risk of laminitis in horses that have underlying endocrine disorders. Medical treatment can also be useful in overweight horses where weight loss has not been achieved despite a restricted diet and exercise program. Your vet can advise you if or when medical treatment is suitable.
• Weight management - managing your horse's weight is the one preventative measure which I feel will have the best chance of having a positive impact when it comes to reducing the risk of laminitis. Excess weight does not categorically mean that your horse will develop laminitis but statistically, excess weight is likely to increase the risk considerably, and when overweight horses get laminitis they tend to suffer far more than horses of normal weight. It is therefore important to monitor your horse’s weight closely so that you can make changes to the diet and exercise plan as necessary. Weight-taping and fat scoring are good ways to monitor weight.
• Restrict grass intake - horses can consume a vast amount of calories when eating grass, especially when it is lush, so restricting their grazing time by using strip grazing, track systems or grazing muzzles can help. Hay and straw can be used as a grass replacement in summer.  Stabling for periods of the day and turnout at night can help too.
• Natural weight loss - burning extra calories to stay warm can help a horse to lose weight. Using a rug with a lighter fill or no rug, when possible, can help an overweight horse burn extra calories in winter. It is also beneficial to avoid treats and high energy feeds.
• Slow them down - encouraging your horse to trickle-feed using small-holed haynets and hay balls can help to slow the consumption of food and prevent horses standing around feeling hungry when their hay has run out.
• Exercise plan - as long as your horse is sound and comfortable, one of the best ways to help manage their weight is to exercise them. A fit horse is a healthy one. An exercise plan will help to burn off fat deposits and avoid further weight gain. If your horse is recovering from laminitis then you must speak to your vet and farrier for advice on when and how to introduce exercise.

More laminitis guides:

How farriery can help laminitic horses

Feeding a horse with laminitis

Other important guides on horse care:

Signs and symptoms of colic in horses - join in with Agria's #ColicCheck to help educate horses owners about common causes and symptoms of colic in horses

Acorn poisoning in horses - all you need to know about poisoning in horses in the autumn

Tick-borne disease - what is it and how does it impact horses

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