# Evaluation of low and high interstitial glucose concentrations in healthy, nondiabetic dogs using a flash glucose monitoring system

## TL;DR

This study shows that healthy, non-diabetic dogs can have low and high interstitial glucose levels, which helps better understand flash glucose monitoring system results in diabetic dogs.

## Contribution

The study provides new data on interstitial glucose variability in healthy dogs using a flash glucose monitoring system.

## Key findings

- 73.7% of dogs had at least one low interstitial glucose concentration (<70 mg/dL).
- Low interstitial glucose was more frequent in smaller dogs (2.5-20.5 kg) compared to larger ones.
- Markedly decreased interstitial glucose (<55 mg/dL) occurred in 63.2% of dogs.

## Abstract

Flash glucose monitoring systems (FGMS; FreeStyle Libre) are useful devices for managing diabetic patients. The FGMS is reportedly accurate for diabetic dogs with hyperglycemia and euglycemia but might underestimate glucose concentrations during hypoglycemia.

Assess the frequency of low and high interstitial glucose (IG) concentrations recorded in healthy, nondiabetic dogs using FGMS.

Twenty-three hospital employee-owned dogs.

Prospective, observational study. The FGMS was placed on all dogs to record ≥488 readings each over up to 14 days. Interstitial glucose concentrations were analyzed to identify the frequency of low, normal, and high IG concentrations. Descriptive statistics were calculated, and comparisons between demographic cohorts were performed.

During monitoring, 73.7% (14/19) of participants had at least one low IG concentration (<70 mg/dL), whereas 26.3% (5/19) had at least one high IG concentration (>180 mg/dL). The mean (±SD) percentage of low and high IG concentrations per dog was 2.8 ± 4.3% and 0.8 ± 2.2%, respectively. Markedly decreased IG (<55 mg/dL) and markedly increased (>250 mg/dL) IG concentrations occurred in 63.2% (12/19) and 10.5% (2/19) of dogs, respectively. The frequency of low IG concentrations in dogs weighing 2.5-20.5 kg (2.2%; interquartile range [IQR], 1.1-5.0) was higher (P = .02) than in dogs weighing 20.6-41.4 kg (0.1%; IQR, 0.0-0.7%); the median difference was 2.1% (95% confidence interval, 0.6-10.1).

Low and high IG concentrations were recorded in healthy, nondiabetic dogs, providing a context for interpreting FGMS results in diabetic dogs.