What Is It?
The term laminitis means inflammation of the laminae.
There are multiple causes.
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Overloading the hindgut with rapidly fermentable carbohydrates such as starch and fructans is the number one cause of laminitis.
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Hydrolyzable carbohydrates that reach the hindgut are fermented, causing an increase in lactic acid production. Acidosis causes the death of many beneficial bacteria, releasing endotoxins, which, in turn, reduces blood flow to peripheral tissues. Soft tissue in the hoof capsule is highly susceptible to damage due to decreased blood flow.
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Mechanical injury can also be a cause (repetitive impact of the hoof on hard ground).
Presenting Symptoms
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Standing with front feet out in front of the body and hind feet further under the body with weight rocked back.
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Hooves warmer than normal, blood in the white line, fever rings visible on hoof wall, pain response when pressure is applied to sole.
- Less activity and a reluctance to move or turn when led.
- Lying down more than is normal.
- Depression.
- ‘Bounding’ pulses in affected legs.
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Many horses with chronic laminitis are overweight, cresty necked, with additional areas of fat deposition.
Dietary and Management Recommendations
- Horses prone to laminitis or suffering from the disease should be fed diets low in hydrolyzable carbohydrates (starch).
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Horses with laminitis should be fed rations well-fortified in vitamins/minerals and amino acids to help with repair of the hoof wall and structures.
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Horses that have suffered from laminitis should not be fed diets rich in starch, as sensitivity to increases in blood sugar and insulin may be present in these horses.
- Some horses may benefit from supplemental magnesium and chromium, both of which assist in increasing sensitivity to insulin.
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If lush pasture is available, horses with laminitis or prone to laminitis should be fitted with a grazing muzzle to prevent excess consumption of forage that contains high levels of fructans (plant sugars). If a muzzle is not an option, placing the horse in a dry lot is preferable to lush pasture.
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Strict weight control and exercise help the laminitic horse immensely.
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Hoof trimming or appropriate shoeing is imperative, particularly in horses that have suffered rotation of the coffin bone.
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Horses with laminitis fare best when left turned out around the clock once the acute phase has passed.