Laminitis

The old saying goes ‘no hoof, no horse’, and with ninety percent of equine lameness originating in the foot it’s important to make sure that we’re aware of some of the most significant foot health problems that our horses may face, one of which is undoubtedly laminitis.

The word laminitis strikes fear into the hearts of horse owners everywhere, and quite rightly so as it is an extremely painful and debilitating disease that requires much ongoing treatment and some essential changes in the management of horses that are unfortunate enough to be afflicted with it.

Early in the year, with the rush of spring grass after a long hard winter, laminitis should be a key concern to owners of horses and ponies predisposed to this condition and in this feature Robert Fowler, chief nutritionist at The Pure Feed Company, gives us an insight into the primary nutritional causes of the disease and what we can do to help prevent its onset.

What is laminitis?
Laminitis is a degenerative disease of the hoof of the horse and at the first signs the horse should be treated as the longer the condition is left to progress, the more permanent the damage will be to the hoof.

Within the hoof of the horse are about 600 pairs of interleaved laminae: the epidermal laminae attached to the hoof wall and the dermal laminae attached to the pedal bone within the horse’s hoof. Laminitis results from an inflammation of these sensitive laminae, which compromises this interaction between the epidermal and the dermal portions and can result in the pedal bone sinking into the bottom of the capsule of the hoof.

When the sensitive laminae become inflamed and the contact with the pedal bone is damaged, the weight of the horse causes the tissues to start ripping, thereby pushing the pedal bone down towards the sole of the hoof. This acute laminar degeneration eventually results in the detachment of the laminae, which then causes the cavity of the hoof to be weakened and the action of the pedal bone being forced downwards destroys the veins and arteries associated with it. With the high concentration of nerves within the horse’s hoof, this inflammation and subsequent progressive damage to the structures within the horse’s hoof is extremely painful and the onset of laminitis is generally accompanied by a dramatic lameness, with the horse adopting a traditional ‘laminitic stance’, leaning back on the heels to try to reduce the pressure placed upon the damaged hooves.

What should be done to help prevent laminitis?
Steps taken to help prevent laminitis occurring are much easier to adopt than ones for the management of a horse or pony that has already developed it, not to mention the welfare benefits to the horse in avoiding this painful disease.

Although the development of laminitis can be as a result of a wide range of factors, including severe concussion or an adverse reaction to certain drugs, nutritional factors are by far the most significant causal factor in the onset of the disease and careful nutritional management is crucial in order to help prevent the problem occurring.

From a nutritional point of view, the most common cause of laminitis is the over ingestion of feed rich in soluble carbohydrates, such as eating considerable amounts of spring and autumn grass (which contains high levels of fructan sugars). Being fed bucket feeds that are high in cereals and molasses can also be a trigger for laminitis, so it’s particularly important to be vigilant in the nutritional management of horses and ponies at these times of year. During the digestion of starches and sugars, a highly acidic environment can develop in the hind gut of the horse, which causes the release of toxins into the bloodstream. It is these toxins that lead to the inflammation of the laminae surrounding the hoof, as a result of restricted blood supply as the toxins constrict blood vessels travelling into the hoof of the horse. This process can damage the sensitive laminae (as discussed earlier) and result in the development of laminitis.

For this reason, it is important to remember that high levels of starch and sugars in the horse’s diet should be avoided. While this is a particularly important principle for horses and ponies that are predisposed to laminitis, this rule in fact forms the basis of all good feeding, with the central feeding principle for healthy horses being the provision of a feeding regime based upon high quality fibre and protein with a good quality vitamin and mineral specification.

Certain types of horses and ponies are more prone to the development of laminitis, with good doers and overweight ponies being particularly sensitive. This is because such animals are by their very nature able to absorb more nutrients from the food they ingest than horses that don’t put condition on quite so easily and as a result, they absorb more of the potentially dangerous starch and sugar from their feed which can put them at risk for laminitis.

By avoiding high sugar, high starch feeds and sticking to one that is very low sugar, high fibre and low starch you will help to reduce the risk of your horse developing this extremely painful disorder.