Health - Laminitis / Founder

Alezane's World of Horses - Health

Laminitis/Founder

Characteristic stance of a horse with laminitis

Laminitis is a very painful condition of the foot. The most simple description of the condition is a failure of the attachment of the pedal bone and the inner hoof wall. The pedal bone is attached to the hoof wall by two interlocking layers of laminae (strong connecting tissues) and, when these tissues for whatever reason get inflamed or the blood supply is disturbed, the attachment between the laminae fail. This results in a tearing of the pedal bone away from the hoof wall and rotation of the pedal bone within the hoof. This can result in varying degrees of change with worst cases involving the pedal bone rotating so much that it sinks within the hoof and its tip penetrates the sole of the foot.

Many "triggers" of laminitis have been identified. The most common cause is the sudden ingestion of an excessive amount of soluble carbohydrates. This is where the horse engorges itself on a lush pasture or breaks into the feed shed and helps itself to the grain. Obese or overweight horses that have little exercise are very vulnerable. Excessive concussion on a hard surface has also been implicated. Laminitis can be a rapid sequel to toxic conditions such as retained placenta or Salmonella enteritis. Older horses that develop Cushing's disease, a hormonal disorder have an increased susceptibility to the condition. Hypothyroidism can also be a predisposing factor in its development. Excessive weight bearing in one limb due to severe lameness in the other may result in the good limb developing laminitis. Therapies using corticosteroids can cause laminitis.

Acute Cases
Laminitis is usually found in the front feet but can be present in all four. Characteristic stance with the forelimbs extended in front with the hind limbs brought forward in an attempt to shift the weight back off the front limbs, as they are usually worst affected. Heat in the feet with a pronounced increase in the digital pulses. Extreme lameness and unwillingness to move forward The horse may be unwilling to lift either front foot off the ground. Painful response when pressure is applied to the sole in front of the frog. Swelling at the coronet may be present.

Chronic cases:
These cases will show most of the acute signs but not as pronounced. The horse may appear stiff. Rings in the hoof wall may be present with the rings being wider at the heel than at the toe.The sole it may have a flat or dropped appearance and can be briused. "Seedy Toe", where there is widening of the white line at the toe with can allow possible bacterial infection. Some ponies that suffer from chronic laminitis have a large thickened neck crest .

When your horse or pony first suffers a laminitis attack, it is very important to respond quickly. Early signs of laminitis can quickly escalate to become quite serious so it is essential contact your vet immediately. Put down a deep-bed if the animal is in the stable so that it has a good cushion under its feet. It is not advisable to walk your horse as the laminae are torn, fragile and you risk doing further damage.

A vet will assess the case and investigate if there is any underlying cause that needs immediate treatment such as a retained placenta. If grain overload is involved your vet may administer liquid paraffin. Initially the focus will be on pain relief as laminitis is a very painful condition. Various other anti-toxic drugs will be administered and drugs that improve the circulation to the feet. Radiographs may be taken to assess if rotation has occurred.

Often the veterinary surgeon will liaise with the farrier and special shoes to support the foot will be applied. In the recovery period it may be necessary to repeat X-rays and reassess shoeing at later stages. Recovery from laminitis is a slow process and it should be considered in months and years not days or weeks. Patience and excellent aftercare are therefore very important in the treatment.
Cases that do recover may be prone to further laminitic episodes. It must also be said that although most cases are usually treatable, laminitis has the potential to result in permanent severe lameness making euthanasia the only option.