Urinary neutrophil gelatinase-associated lipocalin as an early biomarker for acute kidney injury in dogs.

Neutrophil gelatinase-associated lipocalin (NGAL) is used as an early biomarker of renal injury in people. In dogs, increases in urinary NGAL (uNGAL) precede increases in serum creatinine (sCr) in experimental and clinical evaluations of acute kidney injury (AKI) and chronic kidney disease. This study compared uNGAL in two subsets of dogs with AKI and their respective controls. One set included dogs with snake-envenomation at risk for or presenting with International Renal Interest Society (IRIS) grade I AKI; the other group included dogs with AKI, where renal injury was the result of various causes, and IRIS grade was ≥II. Additionally, this study evaluated haemoglobin (Hb) interference during NGAL analysis in Hb spiked urine and plasma from healthy dogs. In both AKI groups, uNGAL was significantly higher than in matched healthy control dogs (P<0.01). Moreover, uNGAL was significantly higher in dogs with IRIS grade ≥II AKI than in dogs at risk of IRIS grade I AKI (P=0.04). In dogs at risk of IRIS grade I AKI, there were no significant differences in uNGAL and uNGAL/uCr between dogs bitten by cytotoxic or neurotoxic snakes (P=0.44). Additionally, Hb did not interfere with the canine NGAL immunoassay. In conclusion, this study confirms the value of uNGAL as a biomarker for early renal damage: uNGAL was significantly increased in dogs with snake-envenomation at risk for or presenting with IRIS grade I AKI, which could be left undiagnosed if evaluated with the traditional renal biomarker sCr. In addition, Hb did not interfere with NGAL measurement in dogs.