TWO Fell ponies from County Durham helped to draw the Great Yorkshire Show crowds to a display by veterinary experts from Liverpool University who are researching a fatal disease peculiar to the breed.

Townend Flinty and her foal, Claremount Cracker, were lent by owner Donald Eltringham, from Trimdon, to illustrate the hardy breed, 10pc of which experts estimate could contract the deadly genetic immuno-deficiency.

Mr Eltringham's mare is no stranger to celebrity status and stood on the Fell Pony Society stand at the Royal Show in 1999 and 2000.

Gareth Thomas, of Liverpool University veterinary immunology department, said the disease caused bone marrow to not function properly and, while not a virus, had similar symptoms to Aids.

The illness appeared unique to Fell ponies and crossbreeds, but there was no theoretical reason why the Dales breed should not also be susceptible.

Mr Thomas, from Cumbria, said no treatment exists and all cases are fatal.

However, research by the university had developed a blood test which could identify the illness in live horses and enable owners to have them destroyed humanely before they suffered badly.

"Our aim really is to try to find a genetic test to identify which animals carry the defective gene, then we can breed it out," he said. "It is similar to a disease called skid in Arab horses and one called blad in Holsteins, both of which are inherited in a similar way and have been pretty much eradicated by breeding out."

One instance of a Fell cross getting the disease proved it could be passed to other breeds, although the gene needed to be present in both sire and dam before the illness could be passed to a foal.

"In this case, a Fell stallion covered a coloured mare and the resulting filly foal was put to another Fell stallion and produced a foal which had the disease."

Mr Thomas, who believes up to 10pc of Fell foals could have the condition, has traced it back to the 1950s, when pony numbers declined following the introduction of tractors.

It was formally identified by Penrith Veterinary Investigation Clinic in the late 1990s.

"Our big breakthrough recently was the blood test for live ponies, before which we could only identify the disease by a post mortem," said Mr Thomas.

He was due to visit the Animal Health Trust this week to present the findings of the research and the organisation is to carry out further work on the subject over the coming year.

The university has funds to continue the research for another year to 18 months