Image copyright Taweesak Anansiriwattana Image caption The anaconda was operated on after an x-ray detected a large tumour near its heart

Thai veterinarians have operated on a 10-year-old anaconda to remove a large tumour from near its heart.

The snake was anaesthetised for the seven-hour operation, Dr Taweesak Anansiriwattana told BBC Thai's Issariya Praithongyaem.

Doctors at Klongluang Animal Hospital had to cut through the skin and abdominal cavity wall in order to reach the tumour, which weighed 1kg (2lb).

Tissue samples have been sent for tests to determine if the snake has cancer.

The snake weighed about 52kg (114 lbs).

Image copyright Taweesak Anansiriwattana Image caption The snake was put on a breathing tube

Image copyright Taweesak Anansiriwattana Image caption It was brought to Klongluang Animal Hospital, north of Bangkok, by a private owner

Most of the tumour was removed but a small part remains as it was too close to arteries, vets say.

The snake was brought to the hospital by a private owner.

Image copyright Taweesak Anansiriwattana Image caption Doctors had to be careful to avoid arteries, as damaging one could have killed the animal