2018 ACVIM Forum Research Abstract Program: Seattle, Washington, June 14 - 15, 2018

Oral and intravenous glucose tolerance tests were performed in 17 healthy Standardbred foals < 72 hours old. Following 1 hour of fasting, a bolus of dextrose (300 or 500 mg/kg) was administered orally or intravenously. Blood incretin and insulin concentrations were measured at 0, 5, 10, 15, 30, 45, 60, 90, 120, 150, and 180 In foals allowed to nurse, incretin concentrations increased above baseline within 15 minutes of nursing. Minimal incretin response with oral dextrose but rapid incretin release after nursing indicates that 500 mg/kg was insufficient for a strong EIA stimulation, that higher dextrose dosing is required, or that factors in milk may be important to activate the EIA in newborn foals. The aim of this study was to determine if hyperinsulinaemia could be reduced and laminitis prevented in insulin-dysregulated ponies, by using the sodium-glucose co-transport 2 (SGLT-2) inhibitor velagliflozin. Forty-nine ponies with varying degrees of insulin dysregulation, based on an oral glucose test (1 g dextrose/kg BW), received either velagliflozin (0.3 mg/kg, p.o., s.i.d., n = 12), or a placebo (n = 37), throughout the study. A maintenance diet of lucerne hay was fed for 3 weeks, followed by a high-NSC challenge diet (12 g NSC/kg BW/day) for up to 18 days. On the second day of the diet challenge blood glucose and serum insulin were measured over 4 h after feeding. Results are expressed as geometric mean (95% CI). The maximum concentration of glucose was lower (P = 0.022) for the velagliflozin group at 9.4 mM (8.0 -11.0) versus 11.9 mM (10. 5 -13.4) Oral glucose tests (OGT) are currently recommended for diagnosis of insulin dysregulation (ID). As horses suffering from ID are prone to laminitis especially when exposed to high amounts of sugar it would be desirable to reduce the amount of diagnostic glucose. Furthermore, a reduced glucose amount enables various routes of application.