"But he is very gentle and obedient, which has made it easier to try and get him used to the process."
Since he was gifted to Sri Lanka in 2001, the elephant, often used to carry Buddhist relics in processions, has spent most of his time at a Buddhist temple in Kalutara, about 75 km (47 miles) from Colombo, the commercial capital.
Perera, who oversees his care, along with a mahout and other staff, said he would probably need hydrotherapy facilities that Sri Lanka lacks to restore full movement.
Thailand will pay for the elephant's journey home, while Sri Lanka has footed the cost of his medical care and food, which runs into about 400 kg (882 lb) a day.
The pachyderm is expected to return to Sri Lanka after treatment, Prime Minister Dinesh Gunawardena has said, and animal welfare activists hope he will be sent to a sanctuary.
Persons:
Read, Sak Surin, Madusha Perera, Muthu Raja, Chiang Mai, Perera, Dinesh Gunawardena, Uditha Jayasinghe, Clarence Fernandez
Organizations:
Sri, Thomson
Locations:
Sak Surin, Sri Lanka, Thai, Thailand, Colombo, Sri, COLOMBO, Sri Lankans, Chiang, Kalutara, Lanka