A stud in Newmarket has closed its doors and halted breeding after an infected horse was found to have herpes.

The herpes infection has forced the Newmarket National Stud thoroughbred breeding site to close.

Five stallions, including Dick Turpin and Pastoral Pursuits, are based at the 500-acre stud based just outside the town.

The infection, which is the deadly neurological strain of the disease, was discovered in a maiden filly which arrived on January 20. The horse was in a health isolation unit at the time.

A statement from the stud, which is owned by the Jockey Club Estates, read: “We regret to report that a case of neurological herpes virus infection has been identified in a maiden filly in the Heath Isolation Unit at the National Stud. The filly arrived from overseas on January 20 2016 and is fully vaccinated.

“We are therefore observing the requirements of the codes of practice and the main stud has now been closed on a precautionary basis; it is hoped that breeding activity can be resumed at the start of the covering [breeding] season.”

Tours of the stud, organised by Discover Newmarket, have also been cancelled until further notice.