08-09-2008 - Developing a DNA test for Fell pony syndrome
Developing a DNA test for Fell pony syndrome
RESEARCHERS at the Animal Health Trust and Liverpool veterinary
school are using funding from the Horse Trust to develop a genetic
test for Fell pony syndrome (FPS
), a severe, fatal immunodeficiency
that affects newborn foals.
The Fell pony breed (pictured right) is categorised as 'at risk' by the Rare Breeds Survival Trust. FPS has emerged over the past decade, and studbook analysis and knowledge of affected foals suggests that it is an inherited disease caused by an autosomal recessive genetic mutation. There was a dramatic fall in the numbers of Fell ponies after the Second World War, and a small number of animals were used to reinvigorate the breed, making it more likely that inherited diseases would appear in subsequent generations.
The syndrome manifests initially as a loss of condition, diarrhoea, coughing and weight loss in foals a few weeks after birth; this is followed by severe anaemia, immune dysfunction and wasting before death. The prevalence is unclear at present, as many animals live and breed on the fells.
A DNA-based test for the mutation that causes the disease would enable carrier animals to be identified and inappropriate matings to be prevented. The test could also be used to detect carrier animals in other breeds; the Fell pony has interbred over the years with breeds such as the Dales pony - which is itself categorised as 'critical' (indicating the highest level of concern) by the Rare Breeds Survival Trust.
'The success of this project will prevent the suffering of newborn Fell pony foals affected with FPS,' says Dr June Swinburne of the AHT, who will be the project leader. 'Foals affected by the condition inherit an incurable genetic defect, which results in severe wasting and a profound anaemia together with multiple infections. Veterinary intervention is in vain and once the condition is diagnosed foals are often euthanased. The gradual but relentless decline in these foals leaves both veterinary surgeons and breeders powerless.
'Breeders are supportive of our attempt to develop a diagnostic test, which will help to prevent carrier-carrier matings, one in four of which results in an affected foal.'