U.S. Customs and Border Protection (CBP) officers at Philadelphia International Airport seized $19,000 in undeclared cash from two travelers heading to the Dominican Republic after an alert from a currency-detection K9 named Nitro.

During an outbound passenger enforcement check, Nitro—a 3-year-old chocolate Labrador Retriever trained to sniff out bulk currency, weapons, and ammunition—alerted officers to a 63-year-old woman and a 79-year-old man attempting to separately board a flight to Santo Domingo.

Though the pair initially claimed they were not traveling together, officers noted they had matching luggage, and the travelers eventually admitted they were companions.

The woman declared $9,000 and the man declared $5,000, but a thorough inspection revealed a combined total of $19,681 in their possession.

Federal authorities seized exactly $19,000 for violating currency reporting laws, remitted the remaining $681 to the couple for humanitarian purposes, and released them without criminal charges.

While there is no legal limit on how much money travelers can move internationally, federal law strictly requires reporting any amounts exceeding $10,000.