The clinical signs and serum concentrations of ibuprofen are reported for 3 canine exposures. No adverse clinical signs or abnormal laboratory parameters were observed when serum ibuprofen concentrations were less than 31 micrograms/mL. Melena and 38 mg blood urea nitrogen/dL (normal 7-26 mg/dL) were present in an animal with a serum ibuprofen of 138 micrograms/mL.