Container: Plain (red top) tube
1. Fast the horse/pony overnight (12 hours).
2. Give a non-glycaemic feed (e.g. chaff) containing 1g/kg bodyweight glucose or dextrose powder mixed with a little water to aid mixing/ingestion.
3. Collect a whole blood (plain tube) sample 2 hours after ingestion of the feed for measurement of insulin concentrations.
Special handling/shipping requirements: No
General information about when this test is indicated:
Resting hyperinsulinaemia is only present in approximately 30% of horses with Equine Metabolic Syndrome (EMS). The in-feed oral glucose challenge test offers a more sensitive means of identifying horses with insulin resistance, one of the hallmarks of EMS. Generally, only the post-prandial insulin concentration is interpreted. Therefore there is no need to collect a basal serum sample for insulin measurement prior to the oral glucose challenge. Measurement of triglycerides and fasting glucose concentrations may be additional tests alongside characteristic changes in the clinical picture that can be helpful in formulating a diagnosis of EMS. Note however very few horses with EMS exhibit fasting hyperglycaemia.
Comparison with other related tests: N/A