GESTATIONAL DIABETES OCCURS IN MARES TOO PREGNANCY-ASSOCIATED LAMINITIS ©
www. jenquine. com
36
HORSE HEALTH: FEEDING FOR BREEDING
FEEDING FOR BREEDING
GESTATIONAL DIABETES OCCURS IN MARES TOO PREGNANCY-ASSOCIATED LAMINITIS ©
© ARTICLE BY: DR JENNIFER STEWART BVSC BSC PHD EQUINE VETERINARIAN, CEO JENQUINE AND CONSULTANT NUTRITIONIST EQUINE CLINICAL NUTRITION
Known as‘ gestational diabetes’ or GDM, pregnancy diabetes affects between 4 and 12 % of women. An equivalent condition occurs in mares and increases their risk of pregnancy-associated laminitis. In both us and horses, the condition is associated with changes in blood glucose and insulin regulation.
The role of insulin is to move glucose out of the blood and into the body tissues( mostly into muscle and liver). At around 12 – 14 weeks pregnancy in women and 27 weeks( 6 – 7 months) in mares, insulin sensitivity begins to drop. This is known as‘ insulin resistance’. It is an evolutionary adaptation which means the mother’ s tissues become less sensitive to the effects of insulin.
This means they take less glucose out of the blood and more glucose can be delivered to the foetus and placenta. In addition to reduced sensitivity to insulin, the amount of insulin released from the pancreas is increased during pregnancy and blood insulin levels rise.
In horses all around the world, all breeds and all disciplines, elevated blood insulin is the number one cause of laminitis. Due to the natural development of insulin resistance during pregnancy, mares are at increased risk for laminitis from 6 months gestation. And it’ s not just the effect of higher insulin levels on the feet – additional stress comes from the increasing body weight borne by the hooves and lack of regular hoof care and farriery. Further, the risk of pregnancy-associated laminitis increases with every pregnancy.
The choice of feed can either protect pregnant mares or increase the risk of laminitis. Feeds that are high in starch and sugar compound the risks( Table 1.) Insulin levels rise faster, peak
www. jenquine. com
AUSTRALIAN QUARTER HORSE ASSOCIATION- www. aqha. com. au