The filly, which arrived at the stud from overseas on January 20, is said to be suffering from the neurological strain of the Equine Herpes Virus (EHV) infection and is in the stud’s Heath Isolation Unit.
The stud has been closed to all but essential workers and visitors as a precautionary measure and the breeding industry’s code of practice for dealing with outbreaks of disease has been put in place.
With thousands of mares from all over the world due to travel to studs in Newmarket over the next few months any spread of the virus, which can result in pregnant mares aborting the foals they are carrying, could be disastrous.
But Newmarket Stud Farmers’ Association chairman Nick Angus-Smith, of Snailwell Stud, said that the very stringent biosecurity measures observed by local studs meant this was highly unlikely.
“In Newmarket, we operate what are probably the strictest standards of hygiene and horse management to be found anywhere in the world and we all stick together and abide by the rules.
“It is a very high-class operation in which every stud sticks rigidly to the guidelines - the National Stud most of all.
“This filly could not be in a better place,” said Mr Angus-Smith.
He emphasised that all mares and fillies have to be vaccinated against EHV before they travel to any Newmarket stud - a rule which has meant the virus occurs here only rarely.
“This particular filly had been vaccinated, but an occasional blip like this is always possible and the chances are there will be no need for any further closures”.
The design for the National Stud, which opened on its current site on land near the racecourse in 1967, was specifically chosen because it was built as a series of isolated yards which could be shut off from one another in the event of an outbreak of disease.