Warendorf (fn-press). The outbreak of equine herpesvirus (EHV-1) at the CES Valencia equestrian competition in Spain is having far-reaching consequences. The German Equestrian Federation (FN) has contacted all German participants in the competition over the past few days and informed them of the infection control measures to be observed during their journey home and upon their return. Unfortunately, it is also clear that, as things stand, four German horses have fallen victim to the virus. To prevent the virus from spreading further, the International Equestrian Federation (FEI) has cancelled almost all international competitions in ten European countries up to and including 28 March 2021 and recommends that national federations also cancel all other competitions. The FN is now implementing this.

National events: In consultation with the regional equestrian federations, all national equestrian events in Germany are cancelled with immediate effect up to and including 28 March 2021. Furthermore, the DOKR is closing the national training centre in Warendorf to external horses and cancelling all central and regional selection courses, as well as the HGW National Junior Show Jumping Championship. In consultation with the breeding associations, the sporting trials for stallions and licensing inspections scheduled for March are also being postponed. The FN, together with its member and affiliated associations, strongly recommends cancelling all other events at which horses from different herds come together. Ongoing events should be halted. These measures are necessary to prevent the spread of the virus. Training at one’s home club or stable is exempt from this, even if the horse has to be transported for this purpose.

International competitions: The FEI has described the outbreak in Valencia as the worst and most aggressive EHV outbreak in recent decades. To prevent the virus from spreading further, the FEI has, as a precautionary measure, cancelled the vast majority of international competitions in France, Spain, Portugal, Belgium, Italy, Austria, Poland, the Netherlands, Germany and Slovakia up to and including 28 March 2021. However, multi-week tours in Vejer de la Frontera (ESP), Vilamoura (POR), San Giovanni in Marignano (ITA) and Gorla Minore (ITA), to which the riders and horses have already travelled, are to go ahead as planned. This will, however, be subject to the strictest infection control measures. The decision to continue these competitions is intended to prevent large waves of people travelling home. However, no new horses are permitted to arrive. Only horses that show no symptoms and for which a health certificate has been issued by the local veterinary authority may continue to leave. Furthermore, these horses must be kept in isolation at their home stables. The FN advises all those returning from travel to contact their local official veterinary officer to agree on further infection control measures.

Background: Last week, the World Equestrian Federation and the FN already suspended all horses that had taken part in competitions in Valencia since 1 February from further competition. Only once these horses have been tested for EHV-1 and the test result has come back negative may they take part in competitions again. The horses’ owners must submit the test results to the FEI and the FN in order to regain eligibility for these horses to compete. This ban applies exclusively to the affected horses, but not to the riders, who may continue to compete in competitions on other horses. Nevertheless, the FN has advised that, as long as the situation at the home stable regarding the presence of equine herpesvirus remains unclear or has not been classified as safe, riders should also refrain from competing with other horses that were not in Valencia.

Measures taken to date: Horses that did not show any symptoms of illness, such as a fever, whilst in Valencia were permitted to leave the competition grounds and be taken home. As the equine herpesvirus is not a notifiable disease in Germany, there are no animal health regulations issued by the veterinary authorities in this regard. The FN has nevertheless called on the riders concerned to exercise increased caution and has provided guidance on the necessary hygiene measures. These include, as a precaution, keeping the horses separate from other horses if they are stabled during the journey home and upon arrival at their home stables, as well as implementing further hygiene measures in accordance with the FN’s hygiene guidelines. This information was initially sent to the German participants in the competitions in Valencia, Oliva and Vejer. Foreign riders based in Germany who are currently in Spain or have recently been there are also being identified and notified. It is also important for all those returning from travel to keep a close eye on their horses and take their temperature regularly so that any potential symptoms can be identified and treated quickly.

Information on equine herpesvirus: As EHV-1 is not a notifiable disease in Germany, there is no precise overview of where outbreaks are currently occurring. According to the FN’s current understanding, it is primarily the competition stables of those riders who have been in Valencia that are affected at present, rather than a large number of clubs and establishments in the leisure or amateur sector. The fact is that, regardless of the incidents in Valencia, cases of herpes occur regularly during the winter months, as the virus is widespread within the equine population. It is therefore always important to adhere to certain hygiene rules in the stables, irrespective of the current outbreak situation. It is helpful in this regard that, due to the coronavirus lockdown, special hygiene and infection control measures must currently be observed in stables anyway. In addition, the following points should always be observed in every stable with regard to the horses:

• Check the horses’ health daily (eating behaviour, general appearance)
•
Take the horse’s temperature regularly if you are aware of outbreaks in the local area• If symptoms such as fever, lethargy, coughing or nasal discharge are present, isolate the affected horse from others and call a vet.
• Do not take sick horses, or apparently healthy horses from premises where there are sick horses, to competitions or other events.
• Use only your own equipment (buckets, halters, lead ropes, rugs, etc.); in other words, do not let horses drink from communal water troughs and only allow them to eat from their own bucket.
• Whenever several horses from different stables come into contact with one another, the risk of infection increases. Therefore, new horses arriving at a stable should initially be isolated and the entire herd closely monitored.
• Humans can also transmit the virus via their hands, clothing and equipment, which is why hygiene and disinfection are particularly important here.

Equine herpesvirus infections do not cause diseases transmissible to humans. Up to 80 per cent of all horses carry the virus. The infection is often asymptomatic. However, once infected, horses continue to carry the virus in a virtually invisible (‘latent’) state, and there is no way to rid these horses of the herpesvirus. Outbreaks of the virus usually manifest as a febrile infection of the upper respiratory tract (the so-called ‘respiratory form’). It is not uncommon for these infections to go unnoticed. However, the rare neurological form of the disease is particularly feared, as it can lead to movement disorders (ataxia), causing the horse to become bedridden and, consequently, often resulting in its death. Late abortion in pregnant mares is another form of the viral disease that is dreaded by breeders.