Nephrotoxic drugs like non-steroidal anti-inflammatory drugs (NSAIDs) and other substances (grapes, raisins, ethylene glycol) are commonly ingested by dogs. The Cornell Companion Animal Hospital emergency service evaluates 60-80 of these cases each year. Clinical reliance on markers of decreased glomerular filtration rate (GFR) such as urine specific gravity serum symmetric dimethylarginine (SDMA), and serum creatinine (sCr) remains the primary method of monitoring for acute kidney injury (AKI). Unfortunately, USG, SDMA and sCr are known to change later in the course of AKI and sCr levels are influenced by more variables than GFR. The utility of an earlier biomarker of AKI is to guide appropriate monitoring and clinical intervention. Earlier intervention would improve outcomes and survival.

This prospective, observational study will test the hypothesis that increases in urinary cystatin B (uCysB) from baseline will predict development of AKI, defined as an increase in serum creatinine of >0.3mg/dL from baseline, earlier than an increase from baseline of creatinine by > 0.3mg/dL and/or SDMA >3μg/dL at 24-, 48-, 72-hours 7 days following presentation. Our study aims to describe the patterns of uCysB elevation in dogs exposed to nephrotoxins and then contrast those patterns with traditional biomarkers of USG and sCr.