A dramatic rescue of two sloth bears was carried out overnight by the Jane Goodall Institute of Nepal, World Animal Protection and Nepali police.

Key points: The once prevalent practice has almost been eradicated by wildlife groups

The once prevalent practice has almost been eradicated by wildlife groups To control the bears, hot needles are used to pierce the nose and thick ropes are inserted

To control the bears, hot needles are used to pierce the nose and thick ropes are inserted An estimated 22,000 bears are caged in bear bile farms in Asia

World Animal Protection said these are the last two known illegal dancing bears in Nepal.

"We are thrilled that the last two … dancing bears have been rescued from their lifetime of suffering," said Manoj Gautam of the Jane Goodall Institute of Nepal.

"After a year of tracking them, using our own intelligence and in cooperation with local police, our hard effort and dedication has helped to bring an end to this illegal tradition in Nepal."

The bears — 19-year-old male Rangila and Sridevi, a 17-year-old female — were found in a distressed state and showed signs of psychological trauma such as cowering, pacing and paw sucking, the animal protection group said.

The bears were taken to Amlekhgunj Forest and Wildlife Reserve for treatment.

The bears were located by tracking the owners' mobile phones.

19-year-old Rangila and 17-year-old Sridevi were taken to Amlekhgunj Forest and Wildlife Reserve. ( Supplied: World Animal Protection )

Mary Hutton, founder of Australian based Free the Bears, described the trade in dancing bears as a "cruel" and "appalling business".

"They are captured as cubs — the mother is usually killed to get to them — and then they are conditioned to behave themselves and obey," Ms Hutton said.

A hot needle is used to pierce the cubs' nose and rope is threaded through and used to control them, she said, adding that the holes are so large and so much pressure is applied from the thick ropes that they never fully heal.

Through punishment and cruelty — which can include dragging the bears onto hot coals — they are trained to dance for tourists who pay a small fee for the entertainment, Ms Sutton said.

Ms Hutton explained that bear owners are mostly living in poverty themselves, barely able to feed their own children, so the bears are usually fed as little as a few pieces of bread a day.

But the good news is dancing bears are almost a thing of the past.

Free the Bears were fundamental in wiping out bear dancing in India in a 15-year campaign that saw about 600 bears rescued.

World Animal Protection have worked with local partners to eradicate the practice in Greece, Turkey and elsewhere.

But while significant gains have been made to end bear dancing, there are still an estimated 22,000 Asian black bears caged in bile farms, where bile is milked from their gallbladder through a permanent hole.

Other threats to all bear species include poaching, wildlife traps and habitation destruction.

"It's extremely distressing to see animals being stolen from the wild and the sad reality is there are more wild animals suffering across the world, purely for the entertainment of tourists," said Neil D'Cruze, Wildlife Technical Expert for World Animal Protection.

"I am pleased that for these two sloth bears at least; a happy ending is finally in sight."