A 10-month-old, intact female Jack Russell terrier was presented about 12 to 13 hours after ingesting approximately one fifth of a tube of 5-fluorouracil cream (Efudex®Topical Solution 5%). She had vomited profusely after ingestion. When vomiting had resolved, she slept for 8 to 9 hours following the incident. When the dog awoke, she resumed vomiting and was inappetent and uninterested in water throughout the day. A history of a “loud murmur” was noted in her medical record.