AN outbreak of Equine Herpes Virus at the show jumping tour in CES Valencia, Spain, has brought jumping to a halt with 17 confirmed cases of the virus as of yesterday (Friday), from 47 horses tested.

Tracing is underway to find animals that had left the show, and venues in the southwest corner of Europe are being extra vigilant.

The FEI Veterinary department was informed last Saturday, February 20th, that four horses that had left the CES Valencia Spring Tour venue on February 14th became sick shortly after returning to their home country (not revealed) and subsequently tested positive by PCR for the neurological form of Equine Herpes Virus type 1 (EHV-1).

Yesterday, the FEI confirmed that there are 17 confirmed cases of EHV-1 onsite and two possible further outbreaks in a third country that can be traced back to Valencia. The show, which was due to run until March 14th, was cancelled last Sunday, in the middle of the Grand Prix.

A total of 752 horses have attended the venue since February 1st. They are now being traced and are currently blocked from FEI competition. In some circumstances, horses that had jumped in Valencia then moved on to other venues.

Kilkenny's Susan Fitzpatrick, who was jumping in Valencia until February 7th, confirmed to The Irish Field that her horses have tested negative for the virus. "It is a huge relief," she said.

Neurological symptoms

Over 150 horses remain onsite. A spokesperson for the FEI said: “A total of 72 horses are showing clinical signs of EHV-1. Of the 47 horses that have been tested, 17 are now confirmed as having the virus.

“Of that number, we are informed that three horses have been transferred to the veterinary hospital with neurological symptoms, but one of these is said to be recovering well and is expected to return to the venue shortly. We are receiving information that there may be additional numbers of horses displaying neurological signs, but do not have any confirmation of that at this point.”

Authorities have sealed off the Valencia venue and declared it an isolation unit. “In order to help alleviate the very difficult situation for athletes, owners and grooms with horses still on the venue in Valencia, the FEI has requested – and received – agreement from the regional veterinary authorities to allow five additional veterinarians onsite to treat the affected horses.

“The FEI is currently organising to get these vets onsite, as well as additional medical supplies that will be delivered to the venue. We have also requested a detailed plan from the regional veterinary authorities on the treatment of sick horses, management of the outbreak, and the plan for getting healthy horses off the venue. We have just received the protocol this afternoon and we are following up directly with them on this.

“We have informed the organisers of the other tours on the Iberian Peninsula of the situation and instructed them that they must not accept any horses that have been competing at Valencia.

“Any horse travelling with a fever is not only a potential carrier and therefore likely to spread the virus to all other horses in the transport, but is at increased risk of developing shipping fever or the more serious neurological form of EHV. Only symptom-free horses should travel and horses leaving Valencia must have their temperature taken prior to travel.”

One high-profile Irish-based show jumper decided against travelling his horses to Europe this week following the outbreak.

What is EHV?

Although there are nine strains of the Equine Herpes Virus, EHV-1 and EHV-4 are the most common. Affected horses may suffer respiratory disease, neurological disease and abortion in pregnant mares. Young foals are also at risk and can die from the infection.

The virus can be transferred through the air from horse to horse up to distances of five metres. Clinical signs of the disease are often seen within 10 days but horses may not immediately display signs of the disease. It is necessary to test horses for EHV at intervals of several weeks to ensure that all affected horses and any in-contact horses have tested negative before horse movements can resume.

A vaccine against EHV-1 is available but does not protect horses against the neurological form of the disease.