AQHA Magazine AQHA May-June YB Low Res | Page 59

PG . 57 preventing grazing may be necessary to prevent laminitis in EMS-prone horses and ponies .
Identification of healthy horses and ponies that are genetically predisposed to EMS before they become affected is the aim . But until genetic testing is readily available , owners should work with their veterinarians to monitor their horses ’ laminitis risk . Knowledge of what ’ s going on with cresty necks and monitoring blood insulin and glucose levels are the cornerstone . Some owners don ’ t recognise that their horse is ‘ fat ’. Picking up on early signs of insulin resistance ie a cresty neck , abnormal hoof growth rings , separation of the hoof wall from the white line and seedy toe as the laminae weaken . Small areas of haemorrhage ( caused by damage to the lamina blood vessels ) in the seedy toe area might also be seen . So keep an eye on those necks and hooves as they likely to be the first sign of disease , and have your veterinarian check your horse ’ s insulin levels .
Horses and ponies with a ‘ cresty neck score ’ of 3 or higher are at greater risk of developing laminitis . Figure 3 . A pony with a cresty neck . A crest neck is an enlarged fat deposit along the neck , identified by the black bar . This pony was assigned a cresty neck score of 3 .
Courtesy : Fitzgerald DM , Anderson ST , Sillence MN , de Laat MA ( 2019 ) The cresty neck score is an independent predictor of insulin dysregulation in ponies . PLoS ONE 14 ( 7 ): e0220203 . https :// doi . org / 10.1371 / journal . pone . 0220203
SUGAR AND STARCH VS BLOOD GLUCOSE & INSULIN : The most common causes of laminitis presented to vets are endocrine ( ie hormonal - especially insulin ) and metabolic disorders – both related to insulin and blood sugar . Early recognition of horses with insulin resistance means preventive measures can be taken earlier – before the disease progresses to laminitis . Excellent research from the University of Queensland confirmed that the amount of neck fat is a reliable sign of insulin dysregulation and a stronger identifier of impending laminitis , than BCS . Eliminating feeds that are over 12 % starch and sugar ( NSC ) and replacement of sugar and starch-based feeds with low NSC feeds ( Table 3 .) underpins dietary management . The term ‘ pasture-associated laminitis ’ describes cases of laminitis that occur in seemingly healthy horses and ponies grazing pasture – between 45 and 60 % of cases occur under these circumstances , and in addition to elimination of sugar / starch / NSC-rich feeds ,
How good are you at assessing how fat your horse is ? https :// www . mdpi . com / 2306-7381 / 9 / 10 / 544
How to score your horse ’ s neck using studies from Queensland University of Technology , Laminitis Survey : https :// cms . qut . edu . au /__ data / assets / pdf _ file / 0009 / 329616 / how-to-assign-a-cresty-neck-score . pdf
Although ponies have a threefold higher prevalence of obesity than horses , Quarter Horses and mixed breed horses had a higher incidence of obesity than Thoroughbreds – and the incidence of ‘ misbehaviour ’ also increases with ‘ fatness ’. The richness and diversity of the gut microorganisms , decreases as horses and ponies gain weight and removing high starch / sugar ( NSC ) feedstuffs from the diet results in a more stable biome , a reduced stress response and less gut discomfort .
Although there are breed and / or individual genetic variations in the risk of EMS and insulin resistance , Quarter horses and ponies are over-represented in laminitis statistics . A single genetic marker associated with laminitis and blood glucose , cholesterol and ‘ insulinresistance ’ ( IR ) has recently been identified in Arabian horses . Several other groups of genes that have been ‘ preserved ’ through evolution and domestication means the potential to develop IR , obesity , EMS and laminitis susceptibility are shared across breeds .
A recent study of 300 Thoroughbreds , Quarter Horses , Warmbloods and mixed-breeds found over 22 % of even normal , healthy horses are unable to regulate their blood glucose and insulin levels . Oft said and nearly always true , prevention is better than a cure so watch those creaty necks and if you ’ re concerned , speak with your equine veterinarian and monitor those blood insulin and glucose levels .
DISCLAIMER : © Dr J H Stewart February 2023 All content provided in this editorial is for general use and information only and does not constitute advice or a veterinary opinion . It is not intended as specific medical advice or opinion and should not be relied on in place of consultation with your equine veterinarian .
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2023 AQHA YEARBOOK ~ MAY / JUNE ISSUE