Learning about laminitis
Joanna Palmer BSc Hons, Nutritionalist, Allen & Page
With the return of spring we can all enjoy a bit of sun and warmth again, but the change in weather also brings with it the flush of grass growth, that without careful management can lead to laminitis in susceptible horses and ponies. However, it is important to remember that there can be many other causes of the disease and whilst ponies, particularly those that are overweight, are most susceptible, it can affect any horse or pony, at any time of the year.
What is laminitis?
Widely recognised as one of the most common causes of equine lameness, laminitis is an extremely painful condition that predominately affects the fore feet, although only one or all four hooves can be affected. Laminitis is characterised by the inflammation of the laminae tissues within the hoof. The laminae form a bond between the hoof wall and the pedal bone, but when inflammation occurs these bonds are weakened. Prompt treatment and careful management means many laminitics make a good recovery.
However, in extreme cases the break down of the laminae leads to rotation and sinking of the pedal bone, which can lead to emergency veterinary treatment.
Although laminitis is most often associated with diet, it can also be brought on by:
- Hoof trauma which can be caused by trot or canter work on hard surfaces, or incorrect farriery;
- Hormonal changes associated with Cushing’s Disease or other metabolic disorders;
- Toxaemia (from a retained placenta after foaling);
- The administration of some medicines such as corticosteroids.
Horses have evolved as trickle feeders and have a digestive system that is perfectly designed for high fibre, grass diets. However, modern pastures include grass that is of much higher quality, containing increased levels of fructans (sugar). This coupled with supplementary feeding of high energy, cereal based feeds which are high in starch, can often lead to dietary induced laminitis.
When a horse eats excessive quantities of sugar rich pasture, or cereal based feeds rich in starch, food passes too quickly through the gut. This leads to the incomplete breakdown of soluble carbohydrates (starch and sugar) in the small intestine. The excess then passes into the large intestine where it is rapidly fermented and lactic acid produced. The resulting acidic environment kills the beneficial bacteria and damages the gut wall. Endotoxins are then released which enter the bloodstream, activating enzymes in the laminae and triggering laminitis.
The first signs of laminitis can vary greatly between individual animals, however, laminitis should be strongly suspected if:
- The horse adopts a ‘laminitic stance’<insert diagram>, with forelegs stretched forwards to distribute weight on to the heels and relieve pressure on the toes.
- The horse is lame and reluctant to move, making only ‘pottery’ strides.
- When walking, the horse puts his heel to the ground before his toe.
- The horse appears uncomfortable, shifting his weight from one foot to another.
- The horse lies down more than usual in an attempt to alleviate the pain.
- A pounding digital pulse is felt in the pastern.
- The coronary band feels unusually warm and the sole of the foot is abnormally sensitive to pressure, however these are symptoms common of many other foot related problems, not just laminitis.
- The horse appears generally ‘off-colour’, with a raised temperature, pulse and/or respiration rate.
Laminitis should always be treated as a veterinary emergency, so call your vet immediately. Early treatment and management of the condition is vital for a successful outcome.
Ensuring horses and ponies maintain a healthy weight is essential as obese animals are far more likely to develop the disease. Diets should be high in fibre, with the starch and sugar content kept as low as possible by avoiding ingredients such as cereal grains and molasses.
Horses and ponies at high risk of developing laminitis should be placed on restricted grazing particularly during periods of rapid grass growth. Strip grazing and using a muzzle are useful ways of maintaining a horse’s natural feeding behaviour at the same time as limiting their grass intake. It is also important to note that fructan levels in grass can be high on days that are cold and sunny, particularly in the mornings and so susceptible horses and ponies should not be turned out until any frost on the grass has melted. Soaking hay for 12-16 hours can also be beneficial, as it will remove soluble sugars, allowing overweight animals or those suffering from laminitis to still be fed sufficient fibre without the additional sugars that can be harmful.
It is important to remember that once a horse or pony has been diagnosed with laminitis they should always be treated as a laminitic as they will be more prone to the condition in future.
For more information on feeding laminitics, call Allen & Page’s friendly, award winning, nutritional helpline on 01362 822 902 or visit