Suspected clinical methemoglobinemia associated with administration of hydrogen peroxide 3% in a dog treated for acute ibuprofen ingestion.

An 8-month-old intact male golden retriever dog was presented to the emergency department of a large private-practice specialty hospital. The dog had become cyanotic and collapsed following administration (orogastric tube) of 1.4 mL/kg of hydrogen peroxide 3% to induce emesis for ibuprofen ingestion. The dog had severe methemoglobinemia (33%; reference range: 0.3 to 1.5%) and developed anemia. The methemoglobinemia resolved after 24 h of hospitalization with supportive care. Results from assessment with high-performance liquid chromatography/tandem mass spectrometry were consistent with ibuprofen ingestion, with no acetaminophen detected. Key clinical message: This case demonstrated methemoglobinemia in a dog following both ibuprofen ingestion and hydrogen peroxide 3% administration.