An Asiatic black bear with a tongue so swollen that it dragged on the ground has been operated upon by a team of vets in Myanmar. The massive tongue that weighed 3kg (6.5lb) and prevented the animal named Nyan htoo from eating normally was removed in a four-hour emergency surgery.

"I've worked with bears for over 10 years and I've never seen anything like it," Heather Bacon from the University of Edinburgh's Royal School of Veterinary Studies, who was one of the experts flown in to Myanmar to operate on the bear, said.

Bacon along with Caroline Nelson, a veterinary nurse at the Animals Asia Bear Rescue Centre in Vietnam and Romain Pizzi from the Wildlife Surgery International worked with local vets to carry out the surgery on Nyan htoo.

The vets think that the swelling may have been caused by the mosquito-transmitted infection elephantiasis, which afflicts people but has never been reported to have affected bears or other animals, the Telegraph reported.

Nyan htoo and his brother were rescued as cubs by monks in Myanmar after they were taken from their mother to be sold illegally, the Telegraph reported.

After the rescue it was discovered that the bear was suffering from an unknown disease, which caused its tongue to become enlarged.

Vets had tried to remove some of the excess tissue to ease the swelling last year. But by June this year the condition began to badly affect Nyan htoo's quality of life, necessitating an amputation.

"We had a lot of discussion and debate because it's a major surgery that you cannot undo but we felt in terms of his quality of life it was the best way to give him as normal a life as possible," Bacon said.

"Having to carry around 3kg of tongue is not normal and that's a lot of weight on his jaw and head. Also, since he was dragging it around on the floor, from a hygiene point of view it's pretty unpleasant and he couldn't ever close his mouth. Now he should be able to close his mouth and manipulate food," the Guardian quoted Bacon as saying.

"It's likely he'll have a period of learning and adaptation because he's obviously never experienced this before."