Longitudinal Prevalence of Hypertension, Proteinuria, and Retinopathy in Dogs with Spontaneous Diabetes Mellitus

BACKGROUND: The prevalence and progression of vascular complications of spontaneous diabetes mellitus (DM) in dogs have not been described. OBJECTIVES: To investigate the effects of duration of disease, as estimated by time since DM diagnosis, and glycemic control on prevalence of systemic hypertension, proteinuria, and diabetic retinopathy in dogs with spontaneous DM. ANIMALS: Seventeen client‐owned dogs with spontaneous DM. METHODS: Prospective, longitudinal observational study. Dogs with DM of less than 1 year's duration were recruited and evaluated once every 6 months for 24 months. Recorded measures included indirect BP, urine albumin, protein and creatinine concentrations, serial blood glucose and serum fructosamine concentrations, ophthalmic examination, and a standardized behavioral questionnaire. RESULTS: Eleven dogs completed the 2‐year follow‐up period, during which the highest recorded prevalence of systolic and diastolic hypertension was 55 and 64%, respectively. Prevalence of microalbuminuria and elevated urine protein:creatinine ratio (UPC) ranged up to 73 and 55%, respectively. Prevalence of retinopathy ranged up to 20%. No significant effect of time since DM diagnosis or glycemic control was detected for any of the measures examined. Additionally, no significant associations between BP, urine albumin concentration, UPC and retinopathy were detected. CONCLUSIONS AND CLINICAL RELEVANCE: With the exception of proteinuria, which was substantial in some cases, clinically deleterious diabetic vascular complications were not identified in dogs in this study.