Trainers and racecourses have been told to be on guard after it was revealed Victor Dartnall's Devon stables have been temporarily shut down following an outbreak of equine herpes virus in the form of equine neurological disease.
Dartnall, whose stables are at Higher Shutscombe near Barnstaple, had runners as recently as Saturday at Wincanton, while his last winners came at Exeter and Chepstow earlier this month.
It is possible his horses may have been carrying the disease before they showed any symptoms and while it is difficult to spread, the British Horseracing Authority is taking every precaution to keep the outbreak under control.
In a statement, Professor Tim Morris, BHA's director of equine science and welfare, said: "We have been working with the trainer and his veterinary surgeon to ensure that the correct, robust security measures have been put in place.
"It is in theory possible that horses may have been infectious before the signs of the disease appeared. We have therefore alerted racecourse, trainer and veterinary representatives to possible exposure, but stress the actual risk of transmission of this virus in a controlled raceday environment is relatively small.
"This emphasises the importance of trainers being vigilant for signs of disease and in particular they should refer to the NTF Code of Practice for Infectious Diseases of Racehorses in Training, which contains specific advice on surveillance and what to do if they have concerns that a horse in their care is showing signs of the disease."
A statement on behalf of Dartnall said: "Over the last few days we have suffered an outbreak of a neurological disease in some horses. Initial test results support the cause to be neurological herpes virus. We are working very closely with our vets and the BHA and we are hopeful that we have the situation under control."
BHA spokesman Robin Mounsey said: "Obviously no entries can be accepted from the stable until the outbreak is cleared.
"The racecourses where Victor's horses have raced in the last couple of weeks have been informed. They will carry out their own procedures for ensuring the racecourse is completely clear of infection.
"They are precautionary as it is a very difficult disease to spread. Everything is being done as a matter of thoroughness. It is dreadful news for Victor's yard. For racing it is an issue that is very easily contained. Victor has done everything spot on. He's quite distraught and it is very sad news for him."
17 June 2013Cecil's words not lost on Ponsonby
Dawn out for Palace redemption
Hawkwood supplemented for Hardwicke
Magician set for Palace showdown
Flotilla To Drop Back In Trip
Cecil's Chigun in Cambridge action
Al Kazeem and Camelot clash again
De Kock hoping to make history
War ready for Royal Ascot battle
Kingdom set to reign over Ascot
Cat clings on for Carroll
Three more winners for Lady Cecil
Monaghan delivers on Midnight
Treve in stunning Diane win
Sapphire target for Trees
Beckett mulls Secret options
Nicholls has broken wrist
16 June 2013Songbird aiming to fly high
Movie has Newmarket on radar
Fahey juveniles primed for action
Stubbs leads O'Brien Coventry team
Salsify on summer break
Kempton target for Benbulben
Top trio head Palace runners
Shea Shea shoots for Stand glory
Animal heads Queen Anne field
Saint-Cloud aim for Dunaden
Magician to be declared for Palace
Soul all heart in York sprint
Kingsgate rules Musselburgh
Sam too sharp for rivals
Hughes makes it pay with Knight
Balding on mark with double
Morawij in a hurry in Scurry
Bartley is queen for a day
Big guns to clash in Coronation
15 June 2013Marengo set for battle royal
Saddler's ready to rock - Oxx
Soprano primed to hit right notes
Balding receives OBE
Victory on a plate for Montaser
Magician run in the balance
Secret set to make Ascot stand
Probert return delayed
Nagle covers Maarek options
Ribblesdale chance for Lark
Walker hoping Guns will fire
Estimate in Royal Gold run
14 June 2013Trip should suit Moore - Dunlop
Vincentti primed for York mission
Guest shoots for Trophy glory
Cleary on sidelines
Dettori partners Cecil hope
Mor success for Bolger and Manning
O'Brien seeking Sham improvement
Plans changing for Kate
Queen's Vase to honour Cecil
Poignant success for Morpheus
Tipperary target for Conor
Approach still on course for Palace
Realta strikes for Channon
Motion trusts Animal instincts
Kazeem set for Camelot rematch