Laminitis – dispelling the myth

How many times have you heard someone say “…it’s only fat greedy ponies that get laminitis…”? 

Science and research tells us this is not the case.  Yes, nutritionally triggered laminitis is very real but there are other factors that can act as a catalyst to the disorder.  These include trauma, illness linked with inflammation and mechanical overload of the hoof.  It is time to dispel the myth and understand that laminitis can be triggered by more than just the lush spring grass.  In this blog we explore the other catalysts you should be aware of.

Defining laminitis

Inflammation of the connective laminae tissue that bonds the hoof wall to the pedal bone.  Due to the hoof wall being solid, when tissues become inflamed, there is no room for expansion and this causes great pain to the horse.  This, in conjunction with the weight of the horse, can result in the pedal bone sinking or rotating within the hoof.  In extreme cases this can result in the pedal bone penetrating of the sole of the foot.

What types of horses or ponies are most at risk?

The answer here is – potentially any horse or pony. There are little restrictions.  Studies have shown though that the older a horse or pony is, the higher the chance.  Older age and breeds of a native origin also appear to be contributory factors.

Understanding the triggers for laminitis

Listed below are five key triggers;

Diseases associated with inflammation

Such as certain types of colic, prolonged diarrhoea, brood mares with a retained placenta and severe pneumonia.  Inflammation throughout the body is thought to lead to inflammation in the hoof laminae.

Diseases associated with endocrine issues

Such as Equine Cushing’s disease or equine metabolic syndrome. With both of these diseases, the horse cannot control its carbohydrate metabolism.  As a result, the horse will produce overly high insulin levels.  Insulin regulates amongst other things; glucose and fat metabolism, inflammation and vascular function.   High levels of insulin stimulate the growth of various cell types by activating insulin-like growth factors that stimulate receptors. Thus initiating the growth of specific cells found in the laminae, contributing to the development of laminitis.

Mechanical overload

Including supporting limb laminitis associated with a fracture or infected joint where the other leg which is bearing all of the weight is at risk of laminitis.  Obesity will of course overload joints and limbs and this can be a factor.  Inadequate blood supply to the laminae due to excessive weight bearing is the key factor here for cause.

Stress or Trauma

Laminitis can stem from repetitive work on hard ground, excessive jumping or over enthusiastic hoof trimming.  Therefore pain in one foot creates a weight transfer to the others.  See above for mechanical overload. Also factor in a dramatic change in environment, build up of stress or a frightening experience. During times of stress and trauma horses produce larger quantities of adrenaline and stomach acid. The acidity in the stomach reacts with the bacteria present to create toxins.  These pass through the stomach wall. Systematically working their way to the feet and attack the sensitive tissues in the hooves.

Nutritionally triggered

High intakes of water soluble carbohydrates; sugars and starch. Excesses of undigested sugars and starch are pushed through to the hind gut. Bacteria breaks down the undigested material causing acidity. The bacteria that can digest fibre are killed off.  As the bacteria die they release toxins into the gut. These are passed into the bloodstream through the gut wall. These toxins interrupt blood flow in the feet, leading to laminitis.

 

In summary…

Numerous factors therefore must be considered.  Advances in modern veterinary medicine and research have shown us this. Any horse or pony can be susceptible to the above and as with most things, prevention is better than cure.  Developing a deeper understanding of this terrible condition and what can cause the onset of it, can help prevent it in the long run. So, the next time someone says “…it’s only fat greedy ponies that get laminitis…”, you know that this is certainly not the case!

 

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