Laminitis

Laminitis is an extremely painful hoof condition affecting 1 in 10 horses and ponies every year ^[1]. In severe cases, permanent damage can be caused to the structure of the hoof. We encourage owners to be on the lookout for laminitis throughout the year, but to be particularly cautious during the sprint and autumn months where we experience surges of grass growth.

If you think your horse, pony, donkey, or mule is suffering with laminitis, you must get in contact with your vet. This crippling condition requires immediate treatment; if undetected or left untreated, it can be fatal.

What exactly is it?

In the centre of the horse’s hoof structure sits the pedal bone, which is held in place by a Velcro-like tissue called the laminae. During an episode of laminitis, the laminae begin to stretch and weaken, allowing movement of the pedal bone within the hoof.

In severe cases of laminitis where the laminae are damaged, the pedal bone can rotate and/or drop through the sole of the foot.

Horses, ponies, donkeys, and mules are all at risk of developing laminitis – although certain breeds of equine are more susceptible due to genetics – all breeds and ages can fall victim to this condition.

Once an equine has experienced laminitis, it is highly likely they will develop it again in the future. Preventative measures should be put in place for these equines, as prevention is always better than a cure.

So what causes it?

There are three general causes which can cause laminitis: hormonal, inflammatory or abnormal weight bearing ^[2].

Being overweight can also more than double the risk of your equine developing laminitis. You can find more information about equine obesity here.

Hormonal disorders such as pituitary pars intermedia dysfunction (PPID, also known as Cushing’s) and Equine Metabolic Syndrome (EMS) are the most common causes of laminitis. Horses with these conditions are at a much higher risk of developing laminitis and their diet and lifestyle should be closely monitored.

Your vet will be able to tell you more information and give advice regarding hormonal disorders.

Inflammatory responses to eating excess amounts of sugar and starch in the diet can result in laminitis. This can happen when a horse has overindulged on grass that’s is fresh and full of sugars – the type of grass often seen in spring and autumn. It can also be triggered by feeds and forages (including hay and haylage) with a high sugar and cereal content.

The hindgut is unable to process these nutrients in large amounts which can result in harmful toxins entering the blood stream, in turn affecting the blood supply and causing damage to the laminae.

Most feed companies will have a nutritionist available if you have any questions or concerns regarding your horse’s diet and right feed.

Abnormal weight bearing laminitis can occur when an equine has suffered an injury and are unable to bear weight on a limb. Because the equine will begin to compensate and add more weight to the opposite limb, increased pressure is added to the laminae in that hoof.

What are the signs to look out for?

The following symptoms may be indicators of laminitis.

1. Subtle lameness or a shorter stride. Lameness can be seen in limbs but may be seen more prominently in the fronts.
2. A bounding digital pulse at the back of the pastern/fetlock. It is normal to always feel a small pulse here as the heart beats, however an equine suffering from laminitis will have increased blood flow to the hoof, resulting in an abnormal pulse, either “bigger” or “bounding” at an increased rate.
3. All round heat in the hooves – Horses can have heat in their hooves after exercising or during hot weather, however if your horse has constant heat in their hooves that does not cool down, you should look for the other signs of laminitis listed here.
4. Weight shifting between feet when resting. A horse will normally stand for a period with a hind foot resting and can be seen weight shifting between the two hind legs. When a horse weight shifts between feet due to pain, it is much more noticeable, happening consistently in a short space of time.
5. Your horse is leaning into its heels. This is known as a “lami stance”, where the horse is relieving the pressure from its pedal bone by leaning onto the back of their hooves. When a horse gets to this point, the laminitis is severe and will most likely need pain relief.

If you think your horse, pony, donkey, or mule is suffering with laminitis, please get in contact with your vet immediately.

Five top tips when on the lookout for laminitis, from Bransby Horses’ lead clinician Lara Gosling:

1. Keep an eye on the weather forecast and your pasture. Avoid turnout first thing if the grass is frosted, and if you are starting turnout again after box rest avoid doing this on frosty days or if there is a sudden warm and wet period causing the grass to grow quickly!
2. Know what is normal for your horse. Check their digital pulses regularly so you know if they change – if you don’t know what is normal it will be hard to know if there is something wrong.
3. Look for subtle lameness. This will help you pick up changes earlier and stop the development of a more severe bout if you can make changes quickly. Walk them in hand on a hard surface each day and do some tight turns – this is when you will most obviously see lameness if your horse is developing laminitis.
4. Be prepared. If you know your horse is prone to laminitis, then be prepared to make changes to their routine quickly. Have a stable or a pen ready where they can be moved to so they are not on grass, have shavings ready to make them a deep bed and have the facilities to hand to start soaking hay.
5. Call your vet. If you are at all concerned that your horse has signs of laminitis, then contact your vet for advice. Your vet will be able to offer advice on management specific to your horse and can support you through making management changes or in a weight loss programme. Your vet can also discuss testing for Cushing’s and Equine Metabolic Syndrome which can often be the underlying cause of many laminitis cases, and then offer treatment options to try and prevent further bouts of laminitis. They can also x-ray your horses’ feet and will work with your farrier if there is a need for remedial farriery or shoeing to help support your horse.

References:

^[1] Pollard, D., Wylie, C. E., Newton, J. R., Verheyen, K. L. P. (2018). Incidence and clinical signs of owner-reported equine laminitis in a cohort of horses and ponies in Great Britain.

^[2] World Horse Welfare, Laminitis: What is it, why do horses get it, and how is it treated?, Advice/Education. Viewed 24/03/2023. https://www.worldhorsewelfare.org/blog/laminitis-what-is-it-why-do-horses-get-it-and-how-is-it-treated