Animals Asia runs a rehabilitation center near Hanoi that houses 160 bears rescued from the trade, but the center has permission to keep only 200 animals. Even if that cap were eliminated, however, the group lacks the funds and space to care for all of Vietnam’s remaining captive bears.

“Obviously, we can’t do this all ourselves,” said Tuan Bendixsen, Animals Asia’s Vietnam director. “The government must take responsibility for their wildlife.”

As Laos ponders how to responsibly close its tiger farms, China is moving in the opposite direction. Since 1992, it has been petitioning Cites to permit trade in farmed tiger products.

When Chinese representatives lobbied for this change once again at the most recent Cites meeting, the proposal was turned down.

Conservationists believe that international pressure may be crucial to persuading Asian governments to close tiger, bear and other wildlife farms, but that strategy’s effectiveness is compromised by an awkward fact: An estimated 5,000 tigers are held in backyards, petting zoos and even truck stops across the United States.

While those animals are predominantly kept as pets, they compromise negotiations with other countries on this issue, said Leigh Henry, a senior policy adviser at the World Wildlife Fund.

“When fingers are pointed at China about their tiger farms, they tend to point the finger back at the U.S. and say, ‘They have as many tigers as we have, why are you not criticizing them?’” she said.

“The priority is closing the tiger farms in Asia,” Ms. Henry said, “but the U.S. needs to set a strong standard, and that starts with cleaning up the situation in our own backyard.”