Diagnostic approach to polyuria and polydipsia in dogs

Abstract

Polyuria (increased urine output, ie, in excess of 50 ml/kg/day) and polydipsia (increased water intake, ie, in excess of 100 ml/kg/day) (PUPD) are very common presenting signs in canine patients. Water consumption can vary considerably from one day to another, so it is very important to quantify water intake before undertaking any investigations to avoid unnecessary and potentially expensive diagnostics. Where is it not possible to measure water intake accurately (eg, in cases where multiple animals drink from the same water bowl), multiple urine samples should be analysed to confirm that urine specific gravity is persistently low. This article outlines a logical diagnostic approach to PUPD in dogs.