Horse Health: Founder, Laminitis

Founder is a term frequently used to describe systemic laminitis. Laminitis usually follows some food-related metabolic disturbance within the horse and results in the partial dysfunction within the hoof. The coffin bone is pulled away from the hoof wall, causing severe pain and lameness.

The laminate (tendons) are responsible for flexing and suspension of the coffin bone inside the hoof capsule. When the epidermal laminae and the dermal laminae do not work together, the laminae may actually tear, impairing the ability of the hoof to function and causing both pain and crippling pathology. (It might be something like tendinitis in humans where one tendon has pulled against another to the point of inflammation and malfunction – only worse.)

Any problem that causes the tendons to swell or the distal phalanx (coffin bone) to pull away from the wall of the hoof is termed “founder”.

Generally speaking, the front of the coffin bone should be parallel to the hoof wall and the lower surface of the coffin bone is roughly parallel to the ground surface.

healthy horse coffin bone

Anything that disturbs this position, forcing the toe of the coffin bone lower and the heel of the bone higher, puts tremendous stress on the hoof sole (from the inside) and causes pain and lameness. (see barefoot) Laminitis can rotate the bone in just this way. The laminae are no longer holding the coffin bone in place, allowing it to rotate and/or fall into the bottom of the hoof capsule.

In severe cases, the entire hoof wall can become separated from the rest of the hoof. Infections between the two parts of the hoof can become severe. The coffin bone is obviously misaligned and the coffin bone can actually pierce through the bottom of the hoof.

It is imperative that the condition be treated immediately. Reducing the swelling and enhancing the circulation to the hoof is the first priority!


  • Increased temperature of the wall, sole and/or coronary band of the foot.
  • A pounding pulse in the digital palmar artery (behind the lower pastern). (The pulse is very faint or undetectable in a cold horse, readily evident after hard exercise.)
  • A flat sole (instead of a nice concave sole) that is either level with the hoof or even protrudes below the actual hoof horn.
  • A depression at the juncture between the leg and coronary band, which is a very smooth transition in a healthy foot. If the hoof makes a shelf, it is a bad sign.
  • Anxiety
  • Visible trembling
  • Increased vital signs and body temperature
  • Sweating
  • Flared Nostrils
  • Walking very tenderly, as if walking on egg shells
  • Repeated “easing” of affected feet
  • The horse standing in a “founder stance” (the horse will attempt to decrease the load on the affected feet). If it has laminitis in the front hooves, it will bring its hind legs underneath its body and put its forelegs out in front called “pointing” (like a hobby horse)
  • Tendency to lie down, whenever possible or, if extreme, to remain lying down.

In mild cases, the tendons swell, circulation is impaired, but actual rotation of the coffin bone is not affected, and (with treatment) the laminitis will usually subside. (see Barefoot).

The picture of the pony hoof at the top of the page is one of those cases. You can see the “rings” on the hoof where her foot has swelled inside the capsule and changed shape as it has grown out of the coronary band. Those rings are an indication of her history over the past 6 months to a year of hoof growth, indicating that she has had incidents of swelling over a period of time. It takes about a year for a horse to regenerate a whole, unaffected hoof.

In her case, her acute lameness subsided in about 3 days with a change in diet and removal of all grain supplementation.

There is also scientific proof that immersing a horse’s feet in ice or 50/50 ice+water for extended periods, sometimes as long as 72 hours at a time, is effective in reducing the severity of injury in acute laminitis. This is a picture of a pony whose owners are immersing her feet in ice immediately. Since she is small, they actually used human muck boots until they could purchase professional ice boots at the farm store (some distance away).

While the picture is whimsical, the condition can be quite serious.

Both ponies will be managed with a drastic decrease in carbohydrates (grain in this case) for the rest of their lives.

Common Causes of Laminitis:

Most frequently seen are problems with Carbohydrate Overload. Sugars cause increase in insulin levels which can cause laminitis. If a horse or pony gets into the sweet feed with an unfettered appetite, founder can result.

Horses that graze on fields fertilized with artificial nitrogen fertilizers can experience metabolic imbalances.

Particularly frequent in Springtime, lush lowland pastures or pastures heavy in clover are much too high in grass sugars. Grazing on this type of grass should be restricted. If permitted, grazing in the morning is best, when grass sugars are lowest.

Rich hay is cut from rye grass and clover pastures designed for fattening cattle. Either avoid or soak these hays for a few hours to lower the sugar content.

Avoid feeding grain unless your horse is active enough to utilize the extra energy. Many people feel they are “treating” their horse with grain rations, but they are actually risking founder. All horses who are not growing, exercising heavily or in foal will do nicely on free choice hay.

Other metabolic situations can cause laminitis. Anything that disturbs the bacteria in the gut can cause gut food fermentation, produce toxins into the blood stream and cause inflammation of the feet. Antibiotics can disturb the gut bacteria. Anything that lowers the body’s pH such as an over-zealous work-out and the build up of lactic acid can cause inflammation (road founder or mechanical laminitis).

Mechanical laminitis can be caused by hooves being subjected to hard-surface work or from habitual pawing.

Some horses are routinely treated with probiotics to aid digestion. If your horse seems particularly sensitive, it is also a good idea to analyze the water content for imbalances and deficiencies as well as pH.

Equine Matabolic Syndrome: Insulin Resistance in Ponies

This article has dozens of amazing photos of the rehabilitation of Glynn: a 22 year old Welsh.

Please note that this advice is neither veterinary nor prescriptive in nature but offered only as an introduction to this topic. Please follow up with extensive research and talk with your veterinarian and other equine specialists if you suspect that your horse has laminitis.

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2 thoughts on “Horse Health: Founder, Laminitis

  1. My 12 year old Paso Fino mare foundered from sudden rich pasture after a long, hard winter. Snow on the ground thru early April and then the sun and warmth brought that grass into hyper drive! One day in early May I noticed she seemed off in the round pen. I called the vet and he suggested I move her to a smaller field with “less” grass. Overgrazed grass. I now know that short overgrazed grass and weeds have more fructans in it then longer grass can. Sugars form at the base. It has been a long hard 16 months of mistakes and well meaning people offering bad advice. Finally my mare is coming round after many subsequent lamanitis flare ups from mis management. The reason for this is I found Dr. Eleanor Kellons ECIR group (Equine Cushing Insulin Resistance). This is all this Dr. Works with. 14,000 case studies strong. This group sells no products and is free. It offers the support of others suffering the same problems and heartbreak. Dr. kellon helped me when other advise failed. ECIR group saved my mare when I was ready to give up.

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