Until recently, pigs have monopolized the truffle-hunting industry. The animals' instinct for rooting behavior makes them naturals at sniffing out the valuable aromatic subterranean mushrooms.

But now the pigs' jobs are going to the dogs, especially in Oregon’s truffle grounds, where the truffle hound-training industry is taking off.

There are many reasons why dogs are replacing pigs. They have more endurance, they're easier to train, and they’re less likely to eat the truffle once they find it.

truffle-hunting dogTruffle hunters say it’s much easier to get a truffle from away from a dog than from a hungry hog.

"The lore is that truffle hunters that use pigs don’t tend to have all their fingers," Charles Lefevre, president and founder of New World Truffieres and organizer of the annual Oregon Truffle Festival, told Modern Farmer.

However, the real advantage of using a dog is that you’re less likely to look like you’re hunting for truffles.

Truffles are a valuable crop — two pounds of rare white Alba truffles can sell for almost $4,000 — so hunting them is often done discreetly. Plus, truffle-harvesting grounds are carefully guarded secrets, and hunters are protective of their turf.

"If you have a pig on a leash, everyone knows what you're doing," Lefevre said. "But if you spot someone with a pooch on a leash, they could just be enjoying some fresh country air."

Oregon dog trainer Glenn Martyn, who's trained bomb- and drug-sniffing dogs since then 1960s, recently branched out into the truffle dog work. He says the principles are pretty much the same.

"The truffle, per se, is not something a dog would naturally search for on its own," he said. "The truffle has to have some association with something. For most dogs, that positive association is food, and once a dog learns the truffle smell means food, they’ll do whatever it takes to find that truffle smell."

Martyn starts training a truffle dog by coating an item in truffle oil and having the dog find it. He buries the item under leaves, then rocks and finally in the soil. Every time the canine successfully finds it, he's rewarded with a treat or favorite toy.

Once the dog masters these exercises, an actual truffle replaces the object, and soon the dog is ready to sniff out the underground delicacies.

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Inset photo: Manfred Klimek/Getty Images