A dog has helped to advance techniques in prosthetics used to give new limbs to victims of the London Bombings.

Coal, an eight-and-a-half year old American bulldog, had to have his left paw amputated because of cancer last year and faced being put down because osteoarthritis in his other legs meant he would have been too weak to stand.

His owner, Reg Walker, a top security guard in the music industry, spent £10,000 on the new limb because he said he could not bear to be without Coal, who travels in his van to gigs and has his own backstage passes to concerts.

Coal's experience, which was the world's second ever operation of its type to an animal, has helped advance the surgery available to humans. Three weeks ago the technique was used in a leg operation for a survivor of 7/7.

Mr Walker said: "When I found out about Coal I was gutted. He goes everywhere with me - he goes on tour, he's the only dog to have aloowed into Live8 and the only dog that has ever been backstage at the Royal Albert Hall. Now he has an absoutely normal quality of life wich he wouldn't have had before."

Noel Fitzpatrick, the vet who carried out the operation on Coal, said the type of implant was the first to be designed so it is compatible with the body's own tissues.

He said: "This is unique in that its the world's only implant into which skin and bone grow. It is the holy grail of research. If you have an accident and your bone sticks out through your shin, skin will try to grow round it. People have been trying for this for years and years -because with this we get an umbrella of skin attached to the metal."

According to Mr Fitzpatrick, founder of Surrey-based Fitzpatrick Referrals, this was only possible because a titanium alloy used has been developed that mimicks animal hide, allowing the skin and the bone from above to seal the metal implant below without it being rejected by the body.

He added: "The coating and implant was developed by Stanmore Implants Worldwide, who are affiliated with University College London. My role was to implant it and to make it work in a dog. It is a step forward in the evolution of technology, starting with a legitimate biological problem in an animal. And then humans who then get implants that will work for them."

See the video of Cole in action here