The deadly seal virus which has killed 700 animals so far is stretching Norfolk's wildlife hospital to the limit.

The Wash has been hardest-hit by the scale of the epidemic which is sweeping northern Europe.

More than 100 seals have so fear been treated at the Royal Society for the Prevention of Cruelty to Animals (RSPCA) hospital at East Winch.

During the last outbreak of Phocine Distemper Virus (PDV) in 1988, half the seal population of northern Europe was killed.

Laila Sadler, from the RSPCA's wildlife department, said: "It's a full-time job just checking the beaches and taking the animals that are sick to hospital."

Newborn pups are especially vulnerable

Currently, RSPCA inspectors are taking an average of five sick seals a day to the hospital near King's Lynn.

However, only 50% survive - and others are being found dead on the beaches.

Now the RPSCA is planning to bring in inspectors from outside East Anglia to help deal with the problem.

Ms Sadler said it was impossible to tell when the epidemic would abate.

"It seems to have accelerated into September.

"It's the breeding season, so there are a lot of vulnerable pups around and the mothers are grouped close together.

"We had hoped this outbreak wouldn't kill as many as last time, but it looks like it could."

The virus has also affected thousands of seals off the coasts of Scandinavia and the Netherlands.