Background: The FreeStyle Libre (Abbott Laboratories) is a flash glucose monitoring system (FGMS) that measures interstitial glucose concentration (IG). The system is factory-calibrated, easy to use, inexpensive, and could be useful for monitoring diabetic cats.Objectives: To evaluate the analytical and clinical accuracy of the FGMS in cats and establish the lag-time between IG and blood glucose concentration (BG).Animals: Twenty client-owned diabetic cats and 7 purpose-bred healthy cats.Methods: Prospective study. Blood glucose concentration was measured using a portable glucose meter validated for use in cats that served as a reference method for IG, as measured by FGMS. In diabetic cats, data were collected for sensor wearing time with different methods of application and accuracy across glycemic ranges. Accuracy was determined by fulfillment of ISO15197:2013 criteria. In healthy cats, lag-time between IG and BG was established after IV administration of exogenous glucose.Results: Good agreement between IG and BG was obtained (r = .93). Analytical accuracy was not achieved, whereas clinical accuracy was demonstrated with 100% of the results in zones A + B of the Parkes consensus error grid analysis. In the immediate 30 minutes after an IV bolus of glucose, when BG was increasing rapidly (approximately 2%/min), IG increased slowly, resulting in a difference of as much as 579 mg/ dL, and no positive correlation between BG and IG was found.Conclusions and Clinical Importance: The FGMS did not fulfill ISO requirements but is sufficiently accurate for glucose monitoring in cats, while considering the lag between IG and BG during periods of rapid changes in BG.

Diabetes mellitus (DM) is associated with a dysfunctional intestinal barrier and an increased risk for systemic infection and inflammation in people, though the pathogenic mechanisms leading to this are poorly understood. Using a canine model of DM, we showed that the peroxisomal proliferator-activated receptor-α agonist fenofibrate modulates plasma lipid profiles and markers of intestinal barrier function. A 3-week course of fenofibrate reduced fasting interstitial glucose and inflammatory cytokine IL-8 and TNF-α concentrations, which correlated with reduced triglyceride levels. The lipidomic profile exhibited significantly lower levels of triacylglycerols, phosphatidylethanolamines, diacylglycerols, and ceramides following fenofibrate administration. On histopathological analysis, we observed an aberrant amount of intraepithelial CD3+ T lymphocytes (IEL) in the small intestine of dogs with spontaneous and induced-DM. Fenofibrate reduced IEL density in the duodenum of dogs with DM and enhanced markers of intestinal barrier function in vivo and in vitro. There were minimal changes in the intestinal microbial composition following fenofibrate administration, suggesting that repair of intestinal barriers can be achieved independently of the resident microbiota. Our findings indicate that lipid metabolism is critical to functionality of the intestinal epithelium, which can be rescued by PPARα activation in dogs with DM.

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Background Day‐to‐day variability impacts safety of insulin therapy and the choice of monitoring strategies. Side‐by‐side comparisons of insulin formulations in diabetic dogs are scarce. Hypothesis/Objectives Insulin glargine 300 U/mL (IGla300) and insulin degludec (IDeg) are associated with less day‐to‐day glucose variability compared to porcine lente (PL) in diabetic dogs. Animals Seven intact male purpose‐bred beagles with toxin‐induced diabetes. Methods In this repeated measured study, PL, IGla300 and IDeg were compared in 2 phases: once‐daily (q24h) and twice‐daily (q12h) administration. Interstitial glucose concentrations (IG) were measured continuously throughout the study. For each formulation, maximal q24h dose was determined using the same algorithm (while avoiding hypoglycemia) and then maintained for 72 hours. In phase 2, 70% of the maximal q24h dose was administered q12h and maintained for 5 days regardless of hypoglycemia. Coefficient of variation (CV) and glycemic variability percentage (GVP) were calculated to determine day‐to‐day and intraday variability, respectively. Results There was no difference in day‐to‐day variability between PL, IGla300, and IDeg in the q24h phase. In the q12h phase, day‐to‐day variability was higher (P = .01) for PL (CV = 42.6 ± 6.8%) compared to IGla300 and IDeg (CV = 30.1 ± 7.7%, 25.2 ± 7.0%, respectively). The GVP of PL was lower (P = .02) compared to IGla300. There was no difference between PL, IGla300 and IDeg in %time IG < 70 mg/dL. Conclusions and Clinical Importance Insulin degludec and IGla300 administered q12h were associated with lower day‐to‐day variability, which might be advantageous in minimizing monitoring requirements without increasing the risk of hypoglycemia.

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Canine diabetes mellitus (DM) affects 0.6% of the canine population and yet, its etiology is poorly understood. Most affected dogs are diagnosed as adults and are insulin-dependent. We compared pan-leukocyte and sympathetic innervation markers in pancreatic islets of adult dogs with spontaneous DM (sDM), spontaneous pancreatitis (sPanc), both (sDMPanc), toxin-induced DM (iDM) and controls. We found evidence of decreased islet sympathetic innervation but no significant infiltration of islets with leukocytes in all disease groups. We show that loss of sympathetic innervation is ongoing in canine DM and does not necessarily precede it. We further found selective loss of islet-associated beta cells in dogs with sDM and sDMPanc, suggesting that collateral damage from inflammation in the exocrine pancreas is not a likely cause of DM in these dogs. The cause of this selective loss of beta cells needs to be further elucidated but overall, our findings are not supportive of an autoimmune process as a cause of sDM in adult dogs. The loss of sympathetic innervation in sPanc in dogs that do not suffer from DM links the disease in the exocrine pancreas to a pathological process in the endocrine pancreas, suggesting pancreatitis might be a potential precursor to DM.

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Background Treatment of diabetes mellitus (DM) in cats typically requires insulin injections q12h‐q24h, posing a major compliance barrier for caregivers. Novel treatments enabling decreased injection frequency while maintaining safety are highly desirable. Insulin fused with feline immunoglobulin fragment crystallizable (Fc) has an ultra‐long plasma half‐life because it recycles through cells where it is protected from proteolysis. Hypothesis Glycemic control can be achieved in diabetic cats with a recombinant fusion protein of a synthetic insulin and feline Fc (AKS‐267c) administered SC weekly. Animals Five cats with spontaneous DM. Methods Cats previously controlled using insulin glargine q12h were transitioned to once‐weekly injection of AKS‐267c. The dose of AKS‐267c was titrated weekly for 7 weeks based on continuous glucose monitoring. Clinical signs, body weight, fructosamine concentrations, and mean interstitial glucose concentrations (IG) were compared between baseline (week 0, on insulin glargine) and the last week of treatment. Data were assessed for normality and compared using parametric or nonparametric paired tests (as appropriate). Results After 7 weeks of once‐weekly injections, compared to baseline, there were no significant changes in clinical signs, body weight (median [range] gain, 0.1 kg [−0.1 to +0.7]; P = .5), fructosamine (−60 mmol/L [−338 to +206]; P = .6), and mean IG concentrations (change = −153 mmol/L [−179 to +29]; P = .3), and no adverse reactions were reported. Conclusion Successful control of clinical signs and maintenance of glycemia was achieved with this once‐weekly novel insulin treatment. The efficacy and safety of this novel formulation should be further assessed in a large clinical trial.