Abstract: Background Flash glucose monitoring systems (FGMS; FreeStyle Libre, Abbott) are convenient and useful devices intended to aid in and improve the management of diabetic patients. The FGMS is reportedly accurate for diabetic dogs with hyperglycemia and euglycemia but tends to underestimate glucose concentrations during hypoglycemia. Hypothesis/Objectives Assess to what extent hypoglycemia, hyperglycemia, and euglycemia are detected in healthy, non-diabetic dogs using a FGMS. Animals Sixteen healthy hospital employee-owned dogs. Methods Prospective, observational study. A FGMS was attached to 16 adult dogs to record at least 488 readings each for up to 14 days. Device-measured interstitial glucose (IG) concentrations recorded the frequency of hypoglycemia, euglycemia, and hyperglycemia. Results 13,067 total IG samples were analyzed. During monitoring, 69% (11/16) had at least one hypoglycemic event (IG < 70mg/dL), while 25% (4/16) had at least one hyperglycemic event (>180mg/dL). The mean percentage of total hypoglycemic and hyperglycemic readings per individual was 3% (range 0-14%) and 0.8% (range 0-8%), respectively. Marked hypoglycemia (IG < 55mg/dl) and hyperglycemia (IG > 250mg/dl) were identified at least one time in 56% (9/16) and 13% (2/16), respectively. When comparing body weight cohorts (2.5-20.5kg vs 20.6-41.4kg), the frequency of hypoglycemic events differed significantly between groups (P=0.021), with the smaller dog cohort having a higher median frequency of hypoglycemia than the larger dog cohort. Conclusions and Clinical Importance Both hypoglycemia and hyperglycemia were recorded by FGMS in healthy dogs. These findings might inform treatment recommendations in diabetic patients and require further evaluation in a larger population.
