Heather Smith Thomas

Laminitis in horses is a very treatable condition but it’s important to detect it in its early stages. Laminitis is the term for inflammation of the laminae. These are tiny finger-like tissues in the horse’s foot—the interlocking “leaves” that attach the living sensitive inner part of the foot (including the coffin bone) to the insensitive outer horn capsule (hoof wall).

When laminitis in horses occurs, a common sequel is complete breakdown of some of the structures of the inner hoof wall that hold the coffin bone suspended in place in the hoof capsule. The damaged laminae tear, allowing the bone to drop. The weight of the horse pushes the bone downward, sometimes pushing it clear through the sole of the foot. The downward push of the coffin bone tears blood vessels, crushes the inner tissues of the sole, and causes extreme pain. This dropping or rotation of the bone is called founder.

Laminitis is usually secondary to an illness or injury. It may be a sequel to colic, severe diarrhea (such as Potomac Horse Fever), pneumonia, uterine infection, etc. Some cases develop after grain overload, or after a horse overeats on lush green grass (grass founder). Laminitis can also occur when one foot or leg is injured and the horse bears too much weight, too long, on the good foot.

The challenge in owning a horse with laminitis is by the time it’s realized the horse is uncomfortable and lame, the damage has a huge head start. Not every case of laminitis progresses to founder, however. If the problem can be detected in the earliest stages, aggressive treatment can often prevent rotation or dropping of the coffin bone and the horse will recover. Detecting this condition early is difficult in many situations, however, since the horse does not show pain until the damage is already well along in this destructive process.

Signs of Laminitis in Horses and Early Treatment

A hoof pick should be on the top of your horse equipment list as frequent cleaning of hooves can make it easier to detect laminitis in horses. By the time a horse starts showing lameness or heat and tenderness in the feet, the damage has already begun. Your veterinarian should be contacted immediately. During the early stage of laminitis, the only sign you might see is a slightly elevated pulse rate. The best way to head off laminitis is to try to prevent it, by not overfeeding grain, not allowing the horse to eat too much lush green grass, and aggressively treating the primary cause of a possible horse hoof problem — colic, diarrhea, retained placenta, etc. If a horse is suffering from an illness that might lead to laminitis, the possibility of laminitis should always be taken into consideration.

Probably the best first-aid treatment for early laminitis in horses is standing the horse in ice-water. A study in Australia in 2009 showed that cold treatment applied to the feet continuously for a day or so can safely and effectively reduce the symptoms and damage in acute laminitis, but you need to start the ice-water treatment immediately.

Laminitis in horses must be detected early for the quickest recovery. By the time the horse enters the acute phase (foot pain and lameness), your window for effectively preventing damage is past. You need to turn this condition around in the first 12 to 24 hours; there is a very short time in which you can reverse it. Icing the feet, along with giving the horse bute (an effective and inexpensive anti-inflammatory drug) and DMSO can help relieve the swelling and inflammation.

DMSO (dimethyl sulfoxide) is very useful as an anti-inflammatory as well. The DMSO can be administered orally by stomach tube by your veterinarian. In earlier years it was given intravenously, but veterinarians have found that it is absorbed just as quickly into the body systems when given orally.

Some veterinarians give DMSO once or twice a day for up to three days since that’s when it is most effective. If a horse still has a big problem after 48 hours, you are in for a long siege of treatment rather than a quick recovery. What you do during the first 72 hours is crucial and the horse will often start showing improvement. More than 80% of horses fully recover with treatment (limiting the horse’s movement, drugs, and foot support). The earlier you start treating laminitis in horses, the better.

It is important to not move the horse at all. Just keep him on soft footing and keep the feet cold. Some kind of foot support should be used, to help prevent damage caused by weight-bearing.

If weight can be spread over the whole hoof, rather than concentrated on the hoof walls (where the compromised laminae are no longer as able to hold the coffin bone in place), there will be less stress on the laminae. Letting the horse stand in deep bedding such as sawdust or on sand (allowing the entire bottom surface of the foot to bear part of the weight) or having your farrier fill the space inside the shoe with a rubber dental impression material so there is weight-bearing on the entire bottom of the foot are methods that can help keep the laminae from tearing.

Most vets and farriers use something on the foot that can be easily put on and taken off — something quick and easy, and temporary. You don’t want anyone nailing a shoe on the foot at that stage, or even gluing — because you don’t want to have to hold a foot up (with added weight on the other foot) while the glue dries. Hoof boots or something like a Styrofoam sole support or wedge taped onto the bottom of the foot can work.

Whatever is used on the bottom of the foot for support must facilitate break-over — from side-to-side as well as at the front. Even if just standing in a horse stall, he will be moving from the water bucket to the feed. Turning as he moves puts pressure on the sides of the foot as well as at the toe. You want to make sure the break-over from side to side is easy, because that’s when the laminae are under the most stress, while turning. The sides and edges of whatever support is put on the foot should be rounded. The wooden clog screw-on shoes that are beveled on all edges of the ground surface work very well.

Helping the Foundered the Horse

From the acute, painful stage, the horse either recovers or the condition becomes chronic with displacement of the coffin bone within the hoof capsule. The bone has changed position — rotating downward at the toe, or sinking. Usually the laminae at the front of the foot are affected the most, so the coffin bone rotates downward in front. If damage to the laminae is extensive (all the way around the hoof), the entire bone drops. These are the most serious cases and the horse may not recover.

If damage to the laminae is extensive (all the way around the hoof), the entire bone drops. These are the most serious cases and the horse may not recover.

You need help from a good farrier as well as your vet, to deal with the damaged hooves. Foot care for a horse with laminitis/founder is aimed at removing forces on the compromised laminae (by reestablishing weight-bearing over the whole bottom surface of the foot and coffin bone), aiding break-over at the toe by moving the break-over point back farther, and decreasing tension on the deep digital flexor tendon at the rear of the foot. The foot can leave the ground easier (the weight doesn’t have to move forward to break over), diminishing the pull of the tendon on the coffin bone at that point of the stride.

New shoeing methods can help, such as glue-on shoes or wooden shoes that can be screwed to the hoof wall without the trauma of nailing. These innovative shoes enable the farrier to move the break-over back, and to apply shoes in a non-traumatic way. It allows placement of the shoe wherever it’s needed to change the area that is bearing weight without creating more pain and trauma by nailing it on. Glue-on shoes are ideal for realigning the coffin bone to a more normal position, especially if the foot does not have enough hoof wall or sole to accomplish this by traditional hoof trimming and shoeing methods.

No matter what kind of shoe is used (with heel wedges, or a glue-on or screw-on wooden shoe), the purpose is to decrease tension on the tendon and provide support—with weight distribution along the whole bottom part of the coffin bone. An analogy would be a person trying to stand on tiptoe with the angle of the bottom of the foot and the ground being about 45 degrees. This creates a lot of stress on the toes. If you place that person’s foot on a board and tip the whole board to 45 degrees, the foot is still 45 degrees to the ground but the weight is shared along the whole foot, relieving all that pressure on the toes. This is why your farrier trims the horse’s heel but replaces it with a wedge or a wooden shoe. You also want the break-over at the toe to be well back, to put less stress on the laminae in the toe.

A radiograph of the foot shows the farrier/veterinarian how much the coffin bone has rotated, and how to trim the foot and/or apply the glue-on or wooden shoe at the proper angle to put the coffin bone in a better relationship with the ground surface. The goal is to get better weight bearing on the whole bone rather than just the tip. Over time, the laminae will hopefully heal, the hoof will regrow, and the horse will be sound again — though some foundered horses will require careful trimming and special shoeing for the rest of their life.

Have you ever dealt with laminitis in horses? Were you able to detect it early for a fast recovery?