Continuous renal replacement therapy is a safe and effective modality for the initial management of dogs with acute kidney injury.

To describe the management of dogs with acute kidney injury (AKI) by continuous renal replacement therapy (CRRT), and to investigate the relationship between a prescribed CRRT dose, the hourly urea reduction ratio (URR), and the overall efficacy. 45 client-owned dogs diagnosed with severe AKI, receiving 48 CRRT treatments at a veterinary teaching hospital. Retrospective study. Search of medical records of dogs with AKI managed by CRRT. Median serum urea and creatinine at CRRT initiation were 252 mg/dL [Inter quartile range (IQR), 148 mg/dL; range, 64 to 603 mg/dL] and 9.0 mg/dL (IQR, 7 mg/dL; range, 4.3 to 42.2 mg/dL), respectively. Median treatment duration was 21 hours (IQR, 8.8 hours; range, 3 to 32 hours). Systemic heparinization and regional citrate anticoagulation were used in 24 treatments each (50%). The prescribed median CRRT dose for the entire treatment was 1 mL/kg/min (IQR, 0.4 mL/kg/min; range, 0.3 to 2.5 mL/kg/min). The median hourly URR was 4% (IQR, 1%; range, 2% to 12%), overall URR was 76% (IQR, 30%; range, 11% to 92%) and median Kt/V was 2.34 (IQR, 1.9; range, 0.24 to 7.02). The CRRT dose was increased gradually from 0.9 mL/kg/min to 1.4 mL/kg/min (P < .001) and the hourly URR decreased from 6.5% to 5.5% (P = .05). The main complication was clotting of the extra-corporeal circuit, occurring in 6/48 treatments (13%). Twenty-four dogs (53%) survived to discharge. CRRT is safe when the prescription is based on the current veterinary guidelines for gradual urea reduction. Treatment efficacy can be maximized by gradually increasing the dose according to the actual URR.