Laminitis

The Disease

Laminitis is a condition affecting the horse’s foot. There is inflammation of what are known as the laminae, which are sensitive structures that hold the bone (pedal bone) in place inside the hoof. There are many predisposing causes of laminitis such as carbohydrate-overload from eating lush grass or excessive amounts of concentrates, gastrointestinal disease, Cushing’s disease, and mechanical factors such as excessive work on hard ground or severe lameness in one of the legs which results in extra weight on the other legs.

Acute laminitis is a serious condition characterised by bounding digital pulses and a lameness of variable degree involving one or more of the feet. The horse may only be slightly lame at the trot through to unable to walk and spending most of the time lying down. The end result of the disease can vary, some horses will recover uneventfully whilst others remain chronically lame and are prone to developing further bouts of laminitis. Another less common but much more catastrophic outcome can also develop in which the pedal bone separates from the hoof wall and rotates or sinks within the hoof to such a degree that it perforates the sole of the foot and the animal must be euthanased for humane reasons.

Treatment

Treatment of laminitis involves:

1. Box rest on a deep bed, preferably of shavings, so that the horse can rest whilst the feet are supported by the bed. Exercise is not recommended, as the feet are painful and it is possible that it may worsen then laminitis.
2. The horse should be fed minimal, and preferably no, grass or concentrates as there is the risk that it may exacerbate the laminitis. Hay is preferable to horsehage or haylage.
3. Overweight horses should lose weight as the excessive weight results in increased pressure on the feet and the risk of laminitis is greater in fat horses.
4. Your veterinary surgeon will recommend appropriate medical therapy. This will probably include ACP (acepromazine), which dilates the blood vessels to the feet thus improving their blood supply, and anti-inflammatory and pain relieving drugs, most commonly phenylbutazone (Bute or equipalazone). In addition, they may increase the amount of support to the foot using specialised bandages or foam supports.
5. Your veterinary surgeon may decide that x-rays of your horse’s feet are necessary in order to determine whether the pedal bones have rotated or sunk within the hooves.
6. If x-ray changes are seen then corrective trimming by your farrier under veterinary guidance may be recommended. In addition, it may be appropriate to have special shoes fitted such as heart bar shoes in order to provide extra support to the foot.
7. If your horse has suffered repeated bouts of laminitis and there is no obvious predisposing cause, then your veterinary surgeon may decide to investigate this further. This may include blood tests to detect equine Cushing’s disease.