This VETgirl podcast reviews the dangers of fluorouracil, also referred to as 5-FU. 5-FU is a topical chemotherapeutic agent commonly prescribed for human actinic keratosis and superficial basal cell carcinomas. When accidentally ingested by dogs and cats, this topical cream can be life-threatening as it has a very narrow margin of safety. In this VETgirl podcast, we discuss toxicosis concerns including decontamination, clinical signs, treatment options, and prognosis. When in doubt, contact the ASPCA Animal Poison Control Center (APCC) for life-saving advice 24/7 as needed!