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AQHA VET NEWS
FINDING THE CAUSE : Many studies have looked at risk factors and the following have been repeatedly identified in horses around the world :
1 . a previous history of laminitis - multiple laminitis episodes is often the first sign of underlying insulin dysregulation 2 . lameness or soreness following routine shoeing / trimming 3 . recent weight gain
Overweight horses tend to become intolerant of sugars ( similar to diabetes in humans ) and are more likely to founder . Many horses that develop laminitis have under-lying hormonal problems including insulin dysregulation ( EMS or equine metabolic syndrome ) and in older horses , Cushings disease . Hormone testing is often recommended on all cases of laminitis . Weight gain is a good predictor of increased risk of laminitis .
Traditionally body condition score ( or just noticing your horse is getting fat !) has been used to assess weight gain but now fat deposition in certain areas has found to be a much more reliable and earlier indicator of laminitis risk . Enlargement of the neck crest is an early sign that a horse is likely developing insulin problems ( similar to increased belly fat in humans ).
Prominent fat pads along the crest of the neck , above the tail head and eye socket or in the sheath / mammary region are predictors that insulin problems and laminitis risk are increasing . Often called ‘ easy keepers ’ these horses also have increased load on the hooves and this also leads to increased risk in overweight animals .
Neck fat takes longer to develop and longer to decrease than other fat storage sites in horses and ponies . Cresty necks are less common when horses are kept in groups and this is thought to be because of competition for feed and more physical activity – and herein lies a key to managing body weight ie less food ( especially sugar and starch ) and more exercise !
PASTURE RISK FACTORS : It ’ s common to think that if your horse is grazing pasture , the diet is steady and constant . But if the starch content of pasture grasses and weeds increases quickly due to a sudden environmental change , a cascade of events that precipitates a laminitis episode can occur . If your horses are on pasture , there may have been changes in the plant sugar levels . Over 50 % of laminitis cases are caused by grazing highsugar pasture or a diet high in sugar / starch . More horses were affected by laminitis in spring and summer than in winter . Proper grazing and feed management could prevent approximately 50 % of laminitis cases , so it ’ s important to know a bit about photosynthesis and also to find out if your horses are sensitive to or becoming sensitive to sugar and starch .
Non-structural carbohydrate ( NSC ) is a measure of the starch , sugar and fructan in grass . High levels are more likely to precipitate laminitis . A change in the levels can occur under many environmental conditions – and be a cause ‘ out-of-the-blue ’ laminitis .
Horses prefer plants that are high in sugar . Plant sugar levels are highest before flowering and drop when seed formation is complete . They can also be high during drought and when night temperatures are low and days sunny . Shade reduces sugar levels ( as plants can ’ t photosynthesize without sunlight ) and overgrazing increases them - because sugar levels are highest in the lower stem . But you need to make decisions about the body condition / neck fatness and soundness of your horse to judge if the grazing time - or if grazing at all - is suitable . Being aware of certain climate and weather conditions that increase plant sugar levels can help with those decisions .
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