Effect of a homemade diet compared to a commercial diet on glycaemic variability and glycaemic control assessed by continuous glucose monitoring system in diabetic dogs: a randomised crossover study.

Objectives: To evaluate the effects of a homemade diet and a commercial diet on glycaemic control and glycaemic variability of diabetic dogs monitored with the FreeStyle Libre continuous glucose monitoring system.

Materials and methods: Prospective randomised crossover study including ten client-owned diabetic dogs on insulin treatment with good glycaemic control. Dogs were randomly assigned to receive either a moderate-fibre (total dietary fibre: 2.2 g/100 kcal ME) homemade diet or a high-fibre (total dietary fibre: 4.8 g/100 kcal ME) dry commercial diet in a 2 × 6-week period. Dogs were re-evaluated every 2 weeks. Clinical and clinicopathological variables, selected continuous glucose monitoring system-derived and glycaemic variability metrics, glucose nadir and postprandial hyperglycaemia were recorded. Differences between diets were analysed by a repeated measure ANOVA fitting a crossover design with pairwise comparisons.

Results: There were no differences in insulin dose and glycaemic control levels between the two dietary periods. The homemade diet significantly reduced serum cholesterol concentration (mean difference: 76 mg/dL; 95% CI: -51.97 to 204 mg/dL). The percentage of time above glucose range was significantly lower (mean difference: -22.5%; 95% CI: -43.9% to -1.08%) and the percentage of time below range higher (mean difference: 6.9%; 95% CI: 1.38% to 12.4%) during the homemade diet period. The percentage of time in range and glycaemic variability metrics were not different between the two diets.

Clinical significance: The homemade diet and commercial diet can be considered valid dietary options in diabetic dogs. The results suggest that, with regard to the diets examined, the homemade diet might have a more effective glucose-lowering effect compared to the commercial diet.