Laminitis

Laminitis is inflammation of the laminae of the foot – the soft tissue structures that attach the coffin or pedal bone of the foot to the hoof wall. The inflammation and damage to the laminae causes extreme pain and leads to instability of the coffin bone in the hoof. In more severe cases it can lead to complete separation of and rotation of the pedal bone within the hoof wall. Laminitis is a crippling condition which can be fatal in severe cases. Once a horse has had an episode of laminitis, they are particularly susceptible to future episodes. Laminitis can be managed but not cured which is why prevention is so important.

Acute symptoms

• Although all four feet can be affected, the forelimbs are more frequently and more severely affected than the hindlimbs.
• Affected horses are reluctant to move and adopt a ‘sawhorse’ stance where they rock their weight back off the more badly affected forelimbs.
• Laminitic horses will often lie down.
• It will be difficult for you to pick up one forelimb due to the severe pain of the other supporting forelimb.
• The hoof wall and coronary band (the soft tissue around the top of the hoof) are often warm to touch.
• There is often pain on application of hoof testers particularly over the toe area.
• Digital pulses are strong and rapid (the digital pulse is found at the back of your horse’s fetlock). If you are uncertain how to check this, ask one of our equine vets to demonstrate.

Chronic symptoms

These are found in cases where the inflammation has existed for some time and structural changes are now evident:

• There are laminitic “rings” on the surface of affected hooves which these correspond to previous episodes of laminitis.
• The hoof wall takes on a dish/slipper shape with long toes.
• Where the pedal bone has rotated in the hoof, there is a bulge in the sole corresponding to the rotated bone.
• The horse has restricted movement in its front legs and will tend to place more weight on its back legs, often described as a ‘laminitic stance’.

Causes

Over-feeding fat ponies is a very common cause, particularly during the spring months after recent rain. The soluble carbohydrate content increases in grass after rain. When ingested, this causes metabolic changes that result in altered blood flow to the laminae of the foot.

Other causes include:

• Over-feeding grain or grain engorgement when a horse gets into a feed shed/bin.
• Retained placenta in post-foaling mares.
• Septicaemic conditions.
• Obesity (a common predisposing factor in laminitic ponies).
• Lameness which prevents weight bearing in one leg leading to laminitis in another supporting limb.
• Trauma resulting from excess work in unshod horses on hard ground, or from over-enthusiastic hoof trimming.
• Hormonal disease such as equine metabolic syndrome and Cushing’s disease.

Diagnosis

If you suspect your horse has laminitis, call us immediately. Depending on the severity of the clinical signs, we will probably need to take some radiographs (X-rays) of your horse’s feet to determine the degree of rotation of the pedal bone within the hoof. This will provide us with a benchmark against which to assess response to treatment and the necessary information from which to work with your farrier to achieve the best possible outcome.

Management

• First, remove the cause. Horses which have developed laminitis as a result of over-feeding need to be removed from the food source immediately.
• Mares with retained placenta constitute a medical emergency.
• Anti-inflammatories are the cornerstone of therapy.
• Affected horses need to be stabled in deep shavings so they can dig their hooves into a comfortable position. In the early stages exercise should be avoided as it may result in further rotation of the pedal bone
• Hoof care is vital. Your farrier should consult with us and trim the hoof according to the degree of rotation of the pedal bone.
• Ongoing dietary management is crucial. We are more than happy to advise on the most appropriate feeding regime. Many feeds promoted as being safe for laminitic horses are not appropriate if your horse is also receiving other feed sources high in soluble carbohydrate.
• Horses need company. You should ensure that horses confined during laminitis treatment are able to interact with other horses.

Prevention

• Ensure your horse or pony is fed a balanced ration appropriate for their type, age and activity level.
• Restrict grass intake by using electric tape to strip graze. Ponies can survive on very little.
• Sometimes turning a horse out at night and bringing it in during the day can help as there are less fructans in the grass at night.
• Do not turn a horse out on lush or frosted grass.
• Call us immediately if you suspect your mare has retained placenta (12 hours later can be too late) or if your horse is otherwise unwell.
• Ensure your horse receives regular hoof care from a reputable farrier.

If you suspect your equine friend has laminitis call us immediately.