Blood donors are urgently wanted to help save lives of a four-legged variety.

In what is believed to be the first scheme of its kind in the country, Richard Leonard, senior veterinary surgeon at Medivet Veterinary Group in Watford Way, Hendon, is appealing for cat and dog owners to enter their animals on its pet donor list.

"We've already lost a cat and a dog this year as a result of being unable to give them blood in an emergency so this would help save more pets' lives," he said.

"The most common problem which results in the need for a blood transfusion is if an animal has a ruptured spleen.

"However, with this database list we'll be able to telephone people whose numbers are on it and all they'll have to do is bring their animal in," he added.

To be eligible, pets have to be healthy, aged between two and eight years old and be up to date with their yearly vaccinations. Cats must weigh between five and seven kilograms and dogs should weigh more than 25kg.

The vet will take up to a pint of blood from a dog and up to 50 millilitres from a cat if needed.

Cats will also need to be tested first for feline Aids and Leukaemia but, Richard says, this takes only five minutes.

The animals' blood type is not important as pets will accept blood groups other than their own for one transfusion.

"Once we've taken blood from the cat or dog we will keep them in for a couple of hours for observation. It's a quick, safe procedure."

A spokeswoman for animal charity RSPCA, London, said: "We welcome the database which we believe may be the first one of its kind in the UK.

"A list of healthy animals is a very good idea especially if it's going to save other animals' lives," she added.

Interested owners should call Hendon's Medivet Veterinary Group, which is open 24 hours a day, seven days a week, on 020 8202 9905.