Laminitis in Horses: Signs, Diagnosis and Treatment

Laminitis affects the sensitive laminae (tissues) of the horse’s hoof. It results in extreme pain, inflammation, and, in some cases, permanent damage to the laminae. Horses, ponies, donkeys, and mules are susceptible to the condition.

What is laminae?

The laminae are interwoven specialised ‘leaves’ of tissue which suspend the pedal bone within the hoof. In mild cases of Laminitis, appropriate treatment will resolve the problem with no lasting effect. If the inflammation is more severe and progressive, the sensitive laminae may lose their blood supply, resulting in loss of support between the pedal bone and horny hoof wall. This can lead to the separation of the pedal bone from the hoof with rotation and/or sinking of the bone within the hoof.

In severe cases, penetration of the sole by the tip of the pedal bone can follow, with fatal consequences.

The condition can strike at any time of year, with spring, summer and autumn being the most prominent months. However, depending on the reason for Laminitis, horse owners should also be aware it can be diagnosed during the winter months too.

The three stages of laminitis

There are three stages to laminitis:

1. Subclinical
   This is the first stage where only microscopic changes are occurring within the hoof and only very subtle signs may be visible. Although hard to identify at this phase, make sure to pay great attention to detail to your horse’s general mood and posture.
2. Acute
   This is the next stage is acute laminitis is more developed which results in extreme pain. Again, pay great attention to detail to your horse’s general mood and posture as these signs could be mistaken for other issues. The earlier laminitis is noticed and diagnosed, the less damage will be caused and the more likely it is your horse will fully recover.
3. Chronic
   Finally, chronic laminitis refers to repeat episodes and horses and ponies who are higher risk of future episodes. Sadly, this stage is where physical changes to the hoof, such as the pedal bone rotating, are much more common.

Symptoms and signs of Laminitis

Laminitis is characterised by lameness involving one or more feet which is often rapid in onset. Most often, both front feet are affected, but hind feet can also be involved. Laminitis can occur in only one foot, often due to excessive load bearing due to a severe lameness of the opposite leg.

Signs of laminitis include:

• Reluctance to move
• Lameness
• Pottery or jarred gait when walking proving sensitive when weight-bearing
• Leaning back on hind legs (when laminitis in front legs)
• Shifting weight between legs
• Heat felt via the hoof wall
• Increased digital pulse in the hoof
• Reluctance to get up when lying down
• Hoof testers will result in a painful response

If you suspect your horse is suffering from laminitis, call your vet immediately. Laminitis is not a condition that can be dealt with without specialist treatment.

Physical examination usually identifies an increase of the digital pulse, and often (but not always) the hoof feels hot. The application of hoof testers to the sole in front of the frog will result in a painful response.

How does a horse get Laminitis?

There is no one cause for laminitis; it is a very complex condition that may be caused by a combination of several different factors. Although research is still being undertaken, these are some of the most recognised causes of laminitis:

• Carbohydrate overload – excess grain or spring grass
• Long term obesity
• Changes in glucose metabolism as a result of endotoxaemia caused by colin, intestinal infections or by infection of the uterus following foaling
• Equine Cushing’s Disease. A disease of older horses and ponies in which an overgrowth of the pituitary gland results in the overproduction of hormones that are thought to be responsible for the recurrent unexplained episodes of laminitis seen in sufferers
• Equine Metabolic syndrome (EMS) usually seen in overweight middle-aged native ponies in which the fat stores become metabolically active and result in insulin resistance and recurrent episodes of laminitis
• Previous damage to the hoof, or historial laminitis
• There is an unproven relationship between high doses of steroids administered to your horse and laminitis. Normal ‘safe’ doses carry a very minimal risk.

Diagnosis of laminitis

The diagnosis is often made on the basis of the above findings at the clinical examination, but X-rays may be needed to formulate a treatment protocol and prognosis.

These X-rays can often be taken at the yard with a portable unit to minimise stress for your horse. The x-ray below shows an advanced form of laminitis where the pedal bone has rotated downwards.

Following diagnosis and a period of treatment, the vet will re-visit and take more x-rays to ascertain whether or not the period of recovery has been effective in any way.

What is the treatment for Laminitis?

If the underlying cause of the laminitis is known, then treatment for the primary disease is indicated. Furthermore, the horse should be on strict box rest in a deep bedding of sand or shavings.

Pain relief will be provided to your horse by your vet in the form of pain-killer anti-inflammatory drugs e.g. bute.

• Diet

Many horses with laminitis are overweight and a specific diet should be discussed with your veterinary surgeon.

In most cases, it will involve a diet of small amounts of roughage only with no other treats. It may seem cruel but is in the best interests of the horse.

It is important though, that your horse still receives adequate nutrition and is not suddenly starved, as this can have potentially fatal consequences.

• Remedial farriery

Hoof care is pivotal in the treatment of laminitis. In the early phase the goal is to stabilise the pedal bone. This can be partially accomplished by transferring weight from the hoof wall to the sole surface, support can be provided with Lily or Styrofoam pads. In the chronic phase the goal is to minimise further rotation and to continue support for the sole, bars and frog with trimming and the use of specialist shoes.

Further investigation

Blood tests may be warranted in the case of Cushing’s Disease or other metabolic disorders to confirm the presence of underlying disease and start additional treatment.

Recurrence

Despite all efforts, some horses experience unexpected relapses, and early detection of these can be essential for your horse’s survival. Discuss with your veterinary surgeon how to detect the early signs and how to feel a digital pulse.

For Laminitis Risk Factors, click here

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