A hippo with toothache was treated by dentistry vets - who used a circular saw to cut away the problem tooth.

The 18-year-old beast named Numchok had recently lost his appetite due to his lower canines overgrowing and biting into his upper gums.

Vets shot the semi-aquatic animal with a tranquiliser dart before holding open his deadly mouth with a huge length of bamboo.

The dentists then set about the unconventional treatment by using a circular saw from a hardware store to grind away part of the sharp ivory tusk that was causing the problem.

Vets at the Khon Kaen Zoo in Thailand said Numchok's lower left canine was shortened by 13cm and his lower right canine by 11cm. They then trimmed two of his upper teeth by 4cm and 5 cm during the procedure on August 26

Zoo director Narongwit Chodchoy said: 'The dental procedure was conducted by veterinarians from the Animal Conservation and Research Institute at the Khao Kheow Open Zoo because Numchok had not been eating in the past few days.

'The procedure also served as an opportunity for new veterinarians and interns to put their knowledge into practice and learn more about hippo teeth.'

Hippos have four giant canines, which are also referred to as tucks, that can grow up to 1.5ft long. They are used for defense and fighting.

They also have 8 incisors, 12 premolars, and 12 molars. All of their teeth are ivory, which has made them the target of poachers in sub-Saharan Africa, where they originate from.