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A 36-kg (79-lb) 12-year-old spayed female Labrador Retriever was referred to the Foster Hospital for Small Animals for evaluation. The dog had a history of profound polyuria and polydipsia of several months' duration. On initial evaluation, the dog was laterally recumbent, and signs of moderate pain in the cranial aspect of the abdomen were noted on palpation. A fundic examination revealed retinal hemorrhages in the right eye and a luxated lens in the left eye. Oscillometric systolic arterial blood pressure was 180 mm Hg, and oscillometric diastolic arterial blood pressure was 100 mm Hg; hypertension was believed to be responsible for the ocular pathological findings. Pertinent findings on CBC, plasma biochemical analysis, and urinalysis included neutrophilia (33.2 × 103 neutrophils/μL; reference interval, 4.9 × 103 neutrophils/μL to 16.9 × 103 neutrophils/μL), hypokalemia (potassium concentration, 2.1 mEq/L; reference interval, 3.7 to 5.4 mEq/L), hypomagnesemia (magnesium concentration, 1.4 mEq/L; reference interval, 1.8 to 2.6 mEq/L), and hyposthenuria (urine specific gravity, 1.005). Findings on thoracic radiographs were unremarkable..