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Ham’s best friend: The beagle brigade is the last line of defense against African swine fever in U.S.

The federal agents keeping our pork supply free from the disease that has killed Chinese pigs work for Pup-Peroni.

Phillip, a beagle, sniffs incoming passengers' luggage with his handler, Valerie Woo, a Customs and Border Protection K-9 officer, at the international arrivals terminal at Dulles International Airport. (Michael Robinson Chavez/The Washington Post)

Phillip has a preference for small handbags. Larger bags may yield bigger loads of contraband, but he doesn’t care. For him, it all pays the same. A single Snausage or, maybe, a Pup-Peroni dog treat. Wearing his dark blue vest that says “Protecting American Agriculture” above the U.S. Department of Homeland Security logo, he alerts. The subject is, at first, oblivious. She has her roller bag, her shoulder bag; she ambles toward the exit.

Phillip’s partner, U.S. Customs and Border Protection K-9 officer Valerie Woo, moves in, makes the collar. From that shoulder bag comes a ham sandwich secured in plastic wrap that Woo says was a snack on the 1:10 p.m. Air China flight arriving in Dulles from Beijing. It is the first of three ham sandwiches Phillip and fellow canine team member Beazley find from that flight alone. Phillip also sniffs out two apples and two oranges.

Prohibited items include meats, fresh fruits and vegetables, plants, seeds, soil and products made from animal or plant materials, the details predicated on a traveler’s embarkation point. But it is the pork that is most troubling right now.

African swine fever is estimated to have killed a quarter of the world’s pork population since last August, including half of China’s swine herd, the world’s biggest. Since then, the disease has spread to Vietnam, Laos, Cambodia, North Korea and the Philippines. It has been reported in Romania, Poland, Bulgaria and other Eastern European countries; in September it was found near Saint-Léger in Belgium. The viral disease has invaded more than 40 countries to date. There is no cure and no vaccine, and although the virus is not dangerous for humans, American pork producers and the U.S. Agriculture Department are terrified it will reach North American soil.

A terrible pandemic is killing pigs around the world, and U.S. pork producers fear they could be hit next

This is the most challenging time of year, says Steve Sapp, public affairs officer of the Mid-Atlantic region for U.S. Customs and Border Protection. International travelers pour in from abroad bearing foodstuffs as gifts, as holiday fare: Grandma’s famous siu mai dumplings or the crispy rice cakes with pork floss the family enjoyed while vacationing in Vietnam. Food is central to the holidays, and experts say human travel is the most likely vector for the disease.

David Ng, a supervisory agriculture specialist for U.S. Customs and Border Protection, estimates officers seize 100 to 400 pounds of contraband at Dulles each day — “99 percent of it food,” he says.

Phillip and Beazley have found mango weevil, pink hibiscus mealybug and citrus canker. They are trained to identify five things: apples, mango, citrus, beef and pork. But right now, the bulk of their olfactory attentions are paid to that last one. The USDA is ramping up its canine presence, adding 60 beagle teams for a total of 179 to expand screenings of incoming international flights, commercial ports, seaports and cargo planes.

Why beagles? They are friendly, nonthreatening and smart, and they have great noses. Also, Woo says this may be the most important: They are exceedingly food-motivated. There are larger breeds patrolling for U.S. currency and firearms, different dogs that sniff out narcotics, still others looking for bombs. Teams at the airport tend to be beagles or beagle mixes, animals plucked from shelters and rescues to get a second chance.

“We could look at 100 dogs and not come back with any,” says Kathleen Warfield, training specialist at the National Detector Dog Training Center in Georgia. “And once they go through initial testing, the percentage of those dogs that make it is maybe 70 percent. We want searching to be their main priority.”

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The dogs start slowly with a progressive training, all positive reinforcement with treats and a clicker, moving from boxes either empty or containing illicit food items to more complicated luggage with its zippers and multiple compartments. They train for 10 weeks, dog and human partner, learning each other, practicing, smelling smells.

“When a beagle walks into a room, they are checking everything,” Warfield says. “They can walk by and smell a whole line of bags or a moving carousel. The dogs save millions of dollars in law enforcement.”


The African swine fever virus can live for months on infected meat or cold cuts, on tainted feed, on animal feed additives. Say it arrived stateside via ham sandwich: That sandwich could be tossed in a dumpster or by the side of the road, and one of the country’s 5 million wild hogs could snarf it, contracting the virus. That virus could then travel via soft tick to domesticated hogs.

The virus has a nearly 100 percent mortality rate for domesticated pigs, leaving slaughter as the only option for disease control. A vaccine to curtail African swine fever has been hindered by a budgetary squeeze that discontinued funding for research at Plum Island Animal Disease Center in 2003. Research into the disease was halted when the USDA transferred responsibility of the Plum Island facility to the Department of Homeland Security. The facility modified its priorities, focusing on foot-and-mouth disease and disbanding the ASF team. Research efforts didn’t resume until 2010, leaving a vaccine still a long way off.

“The one thing you have to recognize now is ASF is on the borders of Western Europe, an endemic disease in half the world,” said Daniel Rock, a researcher who was the lead researcher for the Plum Island ASF team and who is now in the Department of Pathobiology at the College of Veterinary Medicine at the University of Illinois. “The threat for all pig-producing regions has increased exponentially and will remain that way for the indefinite future — a very serious, if not grave, matter.”

He explains that warthogs, wild boar and bush pigs are natural hosts for the virus, often spread efficiently but nonfatally, between wild animals via soft ticks. It is when the virus infects domesticated pigs that the situation becomes dire.

An infection on American soil would likely halt all U.S. pork exports, according to the USDA, a sector that totaled $6.39 billion in sales in 2018.


Phillip trails a woman with an orange reusable grocery bag slung over one shoulder. He sits on alert, looking up at Woo, his human partner. It’s a false alarm, the bag having previously contained another ham sandwich, residual scent molecules detectable only by the beagle’s keen snout.

Why is Air China serving ham sandwiches to passengers in the midst of a pork-borne virus crisis? The airline did not respond to requests for comment.

The job of Woo and fellow K-9 officer Jennifer Jones is location and confiscation, with all confiscated food products destroyed either in the “Muffin Monster” disposal at the airport or via a contract incinerator. They write up “Significant Agricultural Incident Reports,” fruit frequently hacked on a weathered cutting board and samples sent off to a lab in plastic vials for examination by entomologists and plant pathologists. If they determine someone has taken steps to conceal prohibited food items, they issue fines of $500.

The two officers are a peculiar kind of “foodies,” able to list off the most likely contraband depending on the flights’ country of origin. They frequently see pigeon and goat from Egypt; chicharrón from Bogota; doro wat and quanta, a kind of beef jerky, from Ethiopia.

Beazley has found chorizo smuggled in baby formula cans. Phillip and Woo discovered a mummified llama fetus from Bolivia. Michael Litwin, the K-9 supervisor at Dulles, says each airport keeps careful records of the dogs’ successes and failures. The dogs, who work until they are around age 9 before retiring, are not allowed to eat the evidence. And sometimes they make mistakes, like the beagle who became overly enamored of French perfume in luggage.

“They are federal officers, but animals first,” Litwin says.

Phillip pauses just outside the airport’s secondary screening area, where unlucky travelers get additional scrutiny for immigration issues or luggage contraband.

Woo makes a loud kiss sound and says, in a high-pitched voice, “Find it.”

Phillip, golden-eyed and freckled muzzle, listens, trotting off and alerting on a big blue suitcase with a pink ribbon tied around its handle. It’s a false positive, nothing inside but neatly folded shirts and sock balls. No matter. Woo moves on. After all, Phillip is nearly all that stands between us and that one really bad ham sandwich.