Case
A 12-year-old, spayed domestic shorthair cat is presented with polyuria, polydipsia, intermittent inappetence, and occasional vomiting (1-2 times per week) of 4 months’ duration. Physical examination reveals the patient has lost 10% of her body weight since examination 1 year prior; BCS is reduced (3/9), and there is moderate muscle loss.
Mucous membranes are pink and moist with a normal capillary refill time (<2 seconds). Heart rate is 180 bpm, respiratory rate is 24 breaths per minute, and rectal temperature is 101.1°F (38.4°C). Thoracic auscultation is unremarkable, and both kidneys are subjectively small on abdominal palpation. Indirect ophthalmoscopy reveals diffusely tortuous retinal vessels with bilateral bullous retinal detachments (Figure 1). Systolic blood pressure (SBP) obtained via Doppler sphygmomanometry is 170 mm Hg (Table). Serum chemistry profile reveals a creatinine of 2.5 mg/dL (reference interval, 0.23-2 mg/dL), BUN of 33.6 mg/dL (reference interval, 7-27.7 mg/dL), and phosphate of 6.9 mg/dL (reference interval, 2.8-6.8 mg/dL); no other abnormalities are seen.
FIGURE 1 Tortuous retinal vessels with bullous retinal detachments in a cat with systemic hypertension
Hematology profile is unremarkable, except for hematocrit toward the lower end of the reference interval (27%; reference interval, 24%-45%). Urinalysis reveals inactive sediment with a urine specific gravity of 1.014 and urine protein:creatinine ratio of 1.2 (reference interval, 0-0.4). Abdominal ultrasonography confirms both kidneys are small and diffusely hyperechoic with loss of corticomedullary definition, suggestive of chronic nephropathy (Figure 2).
FIGURE 2 Ultrasound image of a kidney that is diffusely hyperechoic with loss of corticomedullary definition in a cat with CKD
International Renal Interest Society (IRIS) stage 2 chronic kidney disease (CKD), substage hypertensive and proteinuric, is diagnosed.
Quiz
Which of the following drugs would be appropriate for this patient?