Laminitis is an intensely painful condition where the laminae within the horse’s hooves are weakened, which can cause the pedal bone to move or even drop through the sole of the hoof. Laminitis is believed to affect 1 in 10 horses or ponies every year (Pollard, D., et al (2018), ’Incidence and clinical signs of owner-reported equine laminitis in a cohort of horses and ponies in Great Britain’, Equine Veterinary Journal. 51(5), pp. 587-594).

Laminitis can have several causes. Any breed can be affected, but native breeds susceptible to Equine Metabolic Syndrome (EMS) are more susceptible.

Hormonal Laminitis: Most causes of laminitis are attributed to an underlying hormonal condition such as Cushing’s Disease or Equine Metabolic Syndrome. Both of these conditions mean that the affected horse is unable to process insulin normally, so levels of insulin within the blood become abnormally high. The link between heightened levels of insulin and the development of laminitis is not clear, but the fact that there is a link is well documented. EMS can also make your horse or pony prone to excess weight gain. If your horse or pony suffers from either of these conditions, it is very important to manage these conditions with direction from your vet, as well as their weight. If you do not know that they suffer from these conditions, but they are overweight, it is important to get on top of their weight to help prevent a bout of laminitis.

Inflammatory Laminitis: The link may be surprising, but digestive upset can lead to inflammation of the laminae. For example, consuming a large amount of sugar and starch concentrates in hard feed in one go, colic, diarrhoea, severe pneumonia or retained placenta after birth can cause inflammation. It is advisable to feed concentrated hard feeds in two separate feeds spread out throughout the day.

Mechanical Laminitis: Some inflammation of the laminae can occur from improper shoeing or trimming, the hooves being left to grow too long, shock travelling through the foot as a result of fast or prolonged work on hard ground, or a fracture, joint infection, or soft tissue damage in the opposite limb. It is therefore important to implement a good farriery schedule whereby your farrier sees your horse on a regular cycle, and to be cautious on roads or especially hard ground. If your horse has had an injury to one leg, keep an eye on the opposite leg for signs of an inflamed laminae.

Lameness is the most prevalent sign of laminitis, usually in at least two feet. Some horses with very mild laminitis will however not appear lame. Lameness can appear as a shortened or pottery gait, reluctance to turn, reluctance to pick up their feet, or lying down a lot. It is often accompanied by a change in temperament, such as a newly aggressive or lethargic disposition. The lameness is likely to show up more when the horse is walking on hard ground or turns tightly. 

Discomfort can manifest as the horse rocking its weight back onto its hind legs when it is standing still to take the weight away from the sore part of the hooves, and this is specifically a tell-tale sign of laminitis. Shifting weight between the feet also indicates discomfort.

The presence of a digital pulse indicates inflammation to the hoof, one possible cause of which could be the onset of laminitis. To feel for a digital pulse, place your index and middle finger at the back, inside or outside of your horse’s pastern. A pulse in this area indicates inflammation to the hoof, and the stronger it is the more inflamed the foot. A digital pulse in both front legs is an indicator of laminitis, whereas a pulse in just one is more likely to be an abscess or injury.

If you suspect a case of laminitis, you must consult with your vet immediately to gain a diagnosis and treat the condition as quickly as possible, as if left to deteriorate, the condition will only worsen potentially past the point of no return. The more inflamed the laminae becomes, the more the pedal bone can move, meaning the less chance your horse has of recovery.

Your vet will discuss with you the signs your horse has been exhibiting, as well as using hoof testers on the point of the frog to test for soreness. They are then likely to take X-rays if there is any chance of the pedal bone having started to move. If laminitis is confirmed, blood tests may be necessary to establish whether the cause has been hormone-related.

If your horse has been diagnosed with laminitis, the first step is to try to manage the amount of pain they are in. Your vet will be able to prescribe an appropriate dose of an anti-inflammatory such as bute.

Box resting your horse is important to control the horse’s food intake, and allows you to support the foot with a deep bed.

Remove or limit sugar and starch from the horse’s diet – instead of grass, they should be fed poor quality hay. Haylage should be avoided, and sugary hard feeds can be replaced with roughage-rich feeds such as unmolassesed chaff or a low sugar mash if you need to give a hard feed for the sake of supplements or routine.

Good remedial farriery including frog supports can help to support the foot.

Management of the condition will entail restricting sugar, so restricting time on sugary grass and staying clear of concentrated, cereal-based hard feeds and treats. The horse will be best off with the bulk of its diet made up of a restricted amount of poor-quality hay, coming in to a stable away from the grass for most of the day. Keeping weight off them is also important, so exercising them as long as they are sound will be a crucial part of your management moving forwards.

Once a horse has had laminitis once, they are prone to suffering the condition again, so following a careful management routine in consultation with your vet is paramount.

For more information on this debilitating but manageable condition, visit https://www.rvc.ac.uk/equine-vet/research/current-projects/laminitis-research