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.
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.
The laminate (tendons) are responsible for flexing and suspension of the coffin bone inside the hoof. 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. (It might be something like tendonitis in humans where one tendon has pulled against another to the point of inflamation and malfunction – only worse.)
Any problem that causes the tendons to swell or the distal phalanx (coffin bone) to pull away from the wall is termed “founder”.
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)
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.
Anything that disturbs this postion, forcing the toe of the coffin bone lower and the heel of the bone higher, puts tremendous stress on the hoof sole and causes pain and lameness. (see barefoot) Laminitis can rotate the bone in just this way.
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 bones is obviously misaligned and the coffin bone can actually pierce the bottom of the hoof.
Symptoms:
- Increased temperature of the wall, sole and/or coronary band of the foot.
- A pounding pulse in the digital palmar artery. (The pulse is very faint or undetectable in a cold horse, readily evident after hard exercise.)
- 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 hindlegs underneath its body and put its forelegs out in front called “pointing”
- Tendency to lie down, whenever possible or, if extreme, to remain lying down.
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 apetite, 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 feedng 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 inflamation 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 inflamation (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 probitoics 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 Ponies
This article has dozens of amazing photos of the rehabilitation of Glynn: a 22 year old Welsh.