I could've sworn that I'd seen beagles at Newark, in international arrivals. I think the distinction is that the BATF use German Shepherds (and other big, fast, scary dogs), but the Ag Dept uses beagles. The beagles also use a different indicators method: when they sniff something interesting, they sit down. When the big dogs sniff something interesting, they start trying to rip into the offending luggage...