Successful Insulin Glargine Treatment in Two Pet Guinea Pigs with Suspected Type 1 Diabetes Mellitus

SIMPLE SUMMARY: This is the first case report of two guinea pigs with insulin-dependent diabetes mellitus (DM) successfully treated with long-acting basal insulin glargine. Both animals presented with typical symptoms and laboratory changes like polyphagia, glucosuria and highly elevated blood glucose levels that suggested the presence of a diabetes mellitus. One of the guinea pigs had asymmetric bilateral cataracts. Mostly, a disorder resembling type II-DM in humans seems to be prevalent in guinea pigs. In this case, the animals did not respond to the standard treatment of a dietary change but responded promptly to insulin treatment. The diabetes has remained controlled for over 1.5 years now. Thus far, there is only sparse scientific information on spontaneous type I diabetes mellitus and treatment modalities in pet guinea pigs. We discuss the current literature including up to date diagnosis, treatment, monitoring with the evaluation of different glucometers and long-time follow-up. Moreover, individual ophthalmic abnormalities and management regarding suspected diabetic cataracts are described in detail. ABSTRACT: Scientific information on spontaneous type I diabetes mellitus (DM) and treatment modalities in guinea pigs is scarce. As most diabetic guinea pigs are overweight and respond to dietary changes, a disorder resembling type II-DM in humans seems to be most prevalent in this species. In the present report, a nine-month-old female intact guinea pig (GP1) was presented because of a cataract and polyphagia. The physical examinations in GP1 and its littermate, GP2, were unremarkable. Laboratory tests revealed hyperglycemia, hyperlipidemia, elevated fructosamine concentrations, and glucosuria in GP1 and GP2. Not responding to dietary changes, an insulin-dependent diabetes mellitus was suspected in both animals. Treatment with 0.5 IU of glargine insulin (Lantus(®)) per guinea pig subcutaneously (s.c.) once daily was initiated in both animals. Monitoring included repeated clinical evaluations and the measurement of plasma glucose and fructosamine concentrations. Capillary glucose concentration was measured using a glucometer, and glucosuria was monitored by dipstick. Blood glucose concentrations decreased quickly in both GPs, and glucosuria resolved. Including several dose adjustments, DM remained controlled for over 1.5 years. Bilateral cataracts and lens-induced uveitis in GP1 were medically managed with only slight progression. This is the first report of guinea pigs with insulin-dependent diabetes mellitus that were successfully treated with long-acting basal insulin glargine.