The laminae are sensitive tissues which attach the pedal bone to the hoof wall. Due to a cascade of metabolic changes these laminae become inflamed and weaken. In severe cases the laminae can fail completely, leaving the pedal bone detached from the hoof wall and able to rotate or sink downward, protruding through the sole.
Cases of laminitis can vary in their severity and prognosis, and whilst every horse or pony has the potential to develop the disease, some are more at risk than others. Once an individual has had laminitis, they are more at risk of suffering recurrent episodes regardless of the initial cause.
CARBOHYDRATE OVERLOAD (Starch/Sugar/Fructan)
Starch and sugar are digested in the small intestine, but when too much is fed some passes into the hindgut where rapid fermentation by resident bacteria causes lactic acid to be produced. This leads to an inflammatory cascade resulting in laminitis.
ENDOCRINE/METABOLIC
90% of laminitis cases have an underlying hormonal cause. Animals that suffer from conditions such as Pituitary Pars Intermedia Dysfunction (PPID or Cushing’s Disease), Equine Metabolic Syndrome (EMS) and Insulin Resistance (IR) will have an increased risk of developing laminitis, with these conditions being characterised by high circulating levels of blood glucose and insulin.
It is proposed that insulin dysregulation plays a key role in the development of laminitis, leading to narrowing of blood vessels, starving the laminae of oxygen and nutrients, eventually leading to tissue death.
SEPSIS/SYSTEMIC INFLAMMATION
A release of toxins due to illness or stress on the body such as colic, retained placenta or infection.
MECHANICAL OVERLOAD/CONCUSSIVE
Less commonly, laminitis can be triggered by lameness in one limb leading to excessive weight baring on the opposite limb, resulting in the development of laminitis in the supporting limb. Excess fast work on hard ground can also lead to concussive laminitis.
The term insulin dysregulation refers to one or any combination of:
Insulin Resistance (IR) - the failure of cells to respond to insulin meaning blood glucose levels remain high
Hyperinsulinemia - a high level of insulin in the blood
An exaggerated release of insulin into the blood after consuming starch or sugar.
LAMINITIS SHOULD BE TREATED AS A MEDICAL EMERGENCY AND VETERINARY ATTENTION SOUGHT IMMEDIATELY
CONSIDER TESTING FOR METABOLIC CONDITIONS. If your horse is showing clinical symptoms of EMS or PPID, discussing testing with your Vet would be worthwhile. Managing these conditions will reduce the risk of them progressing to a laminitis episode.
AVOID HIGH STARCH & SUGAR. Feeds with high levels of cereals or molasses should be avoided, instead look for a feed below 10% combined starch and sugar to help keep blood glucose levels stable.
Grazing that will be high in sugar such as during spring/autumn flushes and frosted mornings should be avoided.
RESTRICT GRAZING
Try not to restrict the amount of time your horse spends out but instead the amount of grass they have access to. Strip grazing, a track system or a grazing muzzle can significantly reduce grass intake.
FEED LOW ENERGY FORAGE
Hay is usually more suitable than haylage, plus has the added benefit that we can soak it for up to 12 hours to reduce sugar and calorie content. Consider having your forage analysed to ensure suitability.
PROVIDE SUPPORT FOR THE GUT
To support the bacterial population of the horse’s gut choose a feed that contains either prebiotics, probiotics, postbiotics or a combination of them all.
MAINTAIN AN IDEAL BODYWEIGHT
Overweight horses/ponies are at a higher risk of laminitis, therefore by maintaining a healthy weight and body condition score, the risk of laminitis developing or reoccurring is reduced. When feeding ensure not to estimate workload to keep calorie levels correct, if they are overweight increasing exercise duration and intensity will help weight loss.
