Background: Microalbuminuria and hypertension have long been associated with a guarded prognosis in human patients with a variety of diseases. In veterinary medicine, tests for microalbuminuria have been used for detecting early kidney damage, but there is little information regarding its association with high blood pressure in dogs with chronic kidney disease (CKD).
Objective: The objective of this study was to evaluate albuminuria and its association with arterial hypertension in dogs with CKD.
Methods: Urinary albumin:creatinine (UAC) ratio, urinary protein:creatinine (UPC) ratio, and systolic blood pressure were determined in 39 clinically healthy dogs and 40 dogs with CKD.
Results: UAC in dogs with CKD (range, 0.002-7.99; median, 0.38) was statistically different from that of control dogs (range, 0.0005-0.01; median, 0.002). Microalbuminuria (UAC 0.03-0.3) and macroalbuminuria (UAC>0.3) were detected in 32.5% and 50% of dogs with CKD, respectively. Sixty percent (24/40) of dogs with CKD had systolic pressure > or =180 mmHg; in these dogs, UAC ratio (range, 0.006-7.99; median, 1.72) was significantly higher than in dogs with CKD and systolic pressure<180 mmHg (range, 0.002-4.83; median, 0.10). Of hypertensive dogs with CKD, those with UPC>1.0 usually had macroalbuminuria, those with UPC 0.5-1.0 usually had microalbuminuria, and those with UPC<0.5 usually lacked albuminuria.
Conclusions: UAC ratio was higher in hypertensive than in normotensive dogs with CKD. Tests designed to detect microalbuminuria may be useful for hypertensive dogs with CKD and a UPC < or = 1.0 to detect the onset and magnitude of albuminuria. Once macroalbuminuria is overt, the UPC ratio itself can be used for the same purpose.