Metronidazole is a prescription antibiotic used in dogs and cats to treat various conditions such as inflammatory bowel disease, nonspecific diarrhea disorders, infections caused by Giardia, and periodontal disease. Metronidazole is not FDA-approved for use in veterinary medicine; however, it is a commonly accepted practice for veterinarians to prescribe this medication for dogs and cats. The actual dose and duration of treatment with metronidazole depends on the specific condition being treated.