Topical Preparations (Toxicity)

Zinc oxide ointments or creams are commonly used as topical skin protectants, astringents, and bactericidal agents. Most ointments contain 10%–40% zinc oxide. Acute ingestion of zinc oxide–containing products usually results in gastric irritation (vomiting) and diarrhea, without the intravascular hemolysis and liver and renal damage associated with ingestion of elemental zinc. Signs are usually seen within 2–4 hr of a significant exposure. Vomiting animals should be managed symptomatically and supportively. Some dogs show hypersensitivity-type reactions manifested by facial and ocular edema. Such cases can be treated with diphenhydramine or other antiallergic medications.