Equine Herpes Virus (EHV)

There are nine strains of the virus, EHV-1 and EHV-4 are most commonly seen. EHV can be spread through the air from horse to horse up to a distance of about 5 metres through coughing and also through close contact. It can also be transmitted on peoples clothes and equipment. Clinical signs vary depending on the strain, EHV 1 is the strain involved in the current outbreak and causes a fever, coughing and nasal discharge. Some horses may develop neurological signs leading to lack of coordination, weakness, difficulty in urinating and defecating and an inability to stand. Horses that are severely affected by the neurological form of the disease may have to be put to sleep. The virus is also a common cause of abortion in pregnant mares and the death of young foals. Horses showing signs of the disease must be isolated and examined by a vet. Clinical signs are often seen within approximately 10 days of being in contact with the virus. Since infected horses can show similar clinical signs to other diseases, we will likely take swabs or blood samples to confirm the diagnosis. Horses that have been in-contact with the affected horse must be identified, isolated and tested for the disease. The movement of all horses on and off the affected site must be restricted and strict biosecurity measures enforced. These measures include foot baths, hand disinfection and the prevention of equipment sharing. Both the FEI and British Equestrian continue to provide regular updates on their websites. British Equestrian have also introduced a self certification form which must be completed for all competitions and training events, to declare your horse is fit and well. You will have been notified about this if its required. We will try to keep you updated as much as we can on the situation here and abroad over the next few weeks.

Now we will move onto discuss the current outbreak of Equine Herpes Virus (EHV-1) in Europe. It began initially in Valencia at an international show jumping event and has now spread to multiple other countries. EHV is found all over the world and has always been present in the UK with occasional cases popping up. We have always recommended vaccination of pregnant mares because of this. However it is the neurological form of the virus which has been seen in Europe which is the most concerning. Unfortunately the vaccine doesn’t cover this neurological form of the virus, but is effective in preventing the respiratory disease and abortion in mares. At present vaccination for competition horses is not mandatory but it may well be for horses travelling to Europe for competitions later in the summer.