Acute nephrotic-range glomerular proteinuria following ibuprofen intoxication in two cats

CASE SERIES SUMMARY: In this report we describe the origin of protein loss and development of acute kidney injury after ibuprofen intoxication in two cats. Two 13-month-old neutered male domestic shorthair siblings were presented with acute kidney injury (AKI) and severe glomerular proteinuria following witnessed ibuprofen intoxication 3 days prior. Both cats presented with severe azotaemia (creatinine >900 µmol/l [>10 mg/dl]) and severe proteinuria (urine protein:creatinine [UPC] >20, normal <0.5). Urine protein electrophoresis upon presentation revealed mainly albumin and primary glomerular protein losses. The proteinuria and azotaemia resolved completely within 5 days of hospital treatment (8 days after ingestion). Urine protein electrophoresis, once the azotaemia and proteinuria resolved (UPC 0.11; normal <0.5), had a similar pattern to the one from admission. Both cats made a full recovery with supportive care. RELEVANCE AND NOVEL INFORMATION: This is the first clinical report of AKI with nephrotic-range protein losses following ibuprofen intoxication in cats. We propose that this finding is due to idiosyncratic glomerular injury, as described in humans.