Tooth extraction was more like excavation for Keighley vets Andrew Greenwood, pictured, and John Lewis and their specialist team.

The patients were ten-ton walruses and the team's task was to remove their massive tusks - each weighing more than 12lbs.

The vets, partners at Keighley-based International Zoo Veterinary Group, travelled out to Moscow to join a group commissioned especially to do the job.

The eight walruses were suffering from infected tusks - damaged on the concrete enclosures in Moscow Zoo.

But thankfully, they were tame enough for the vets' team to approach.

Penny Cusdin IZVG research assistant, said Andrew and John were involved in the medication and controlling the anaesthetic.

"They had to set up all the equipment and it was not a normal situation - walrus lung capacity is so big, even bigger than a horse.

"I understand they had to adapt a bucket for a face mask."

The tusks are also oblong in section so they were impossible to twist to get out. It took up to an hour and a half to remove each one.

She said there was also a danger that the animals would stop breathing.

"Walruses hold their breath when they dive underwater which means they can stop breathing under anaesthetic. It was a very stressful job for both vets," she added.

The teeth were removed by British dental surgeon Peter Kertesz, who, Monday to Thursday, deals with people and on Fridays with animals, she added.

The practice is the only one outside the US to offer freelance veterinary services to non-domestic animals and the vets work all over Europe.

Last year it spearheaded an investigation into the number of wolf-dog hybrids in the UK.

And it has just completed a report for the Department of Education, Transport and the Regions on the new Dangerous Wild Animals Act.