Laminitis, in its simplest form, is inflammation of the sensitive layers (laminae) of the hoof resulting in pain, and in some cases, permanent damage to the laminae. The laminae are interwoven ‘leaves’ of tissue which suspend the pedal bone within the hoof. In very mild cases, appropriate treatment will resolve the problem with no lasting effect.
However 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 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.
Laminitis is often rapid in onset and is characterised by lameness involving one or more feet. Most often both front feet are affected, but hind feet can be involved as well. Occasionally laminitis occurs in only one foot, often as a result of excessive load bearing due to a severe lameness of the opposite leg.
Affected horses show a characteristic, pottery gait landing with the heel first. The condition is much worse when asked to walk on a firm surface or when turning. When resting, they often weight shift and stand with the hind limbs placed further underneath the body.
Physical examination usually identifies an increase of the digital pulse and often (but not always) the foot feels hot. Application of hoof testers to the sole in front of the frog will result in a painful response.
The diagnosis is usually made from the above findings at the clinical examination, but x-rays may be needed to formulate the treatment regime and prognosis.
To minimise stress for your horse, these x-rays can often be taken on the yard using a portable unit.
WHAT ARE COMMON CAUSES OF LAMINITIS?
•Carbohydrate overload - excess grain or spring grass.
•Changes in glucose metabolism as a result of endotoxaemia caused by colic, intestinal infections or by infection in the uterus (womb) following foaling (retained placenta).
•Horses with Equine Cushing’s Disease are more predisposed to laminitis
•Equine Metabolic Syndrome also presents an increased risk of laminitis.
•There is also an unproven relationship between high doses of steroids and laminitis. Normal ‘safe’ doses carry a very minimal risk however.
If the underlying cause of the laminitis is known, then treatment can be tailored accordingly.
The horse or pony should be on strict box rest in a deep bedding of sand or shavings with pain relief provided by your veterinary surgeon in the form of pain-killer anti inflammatory drugs.
Many horses with laminitis are overweight and a specific diet should be discussed with your vet.In most cases this will involve small amounts of roughage only with no other treats. It may seem cruel, but is in the best interests of the animal.
It is important however, that your horse still receives adequate nutrition and is not suddenly starved, as this can have potentially fatal consequences.
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 achieved 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.
In some cases, e.g. Cushing’s Disease or other metabolic disorders, blood tests may be needed in order to confirm the presence of underlying disease and start additional treatment.
Despite all efforts some horses experience unexpected relapses, and early detection of these can be essential for your horse’s survival. Discuss with your vet how to detect the early signs and how to feel a digital pulse.
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