Neurological EHV-1 confirmed in a racehorse in Yorkshire

June 2, 2017 |

As reported by the Racing Post on 1st June 2017, the neurological form of equine herpesvirus-1 infection (also referred to as paralytic EHV-1) has been diagnosed at post-mortem in a racehorse in Kevin Ryan’s Hambleton yard in North Yorkshire. Standard and well-rehearsed control measures have been put in place by the British Horseracing Authority (BHA) who are working closely with the yard’s attending veterinary surgeon and the Animal Health Trust to now assess the extent of the infection within the yard and to minimise risk of spread by ensuring that the yard only resumes normal operations when it is considered safe to do so and on the basis of absence of clinical disease and clear laboratory tests. As a precaution, the BHA have also restricted two premises that have horses that recently shared transport with healthy animals from Mr Ryan’s yard. There is currently no suggestion of neurological EHV-1 on these two other premises, but tests are being conducted to rule out presence of the infection and provide assurances to racing.

The TBA would like to assure its members that whilst this sounds like a worrying situation, it is not considered exceptional as EHV-1 periodically emerges in the form of abortion in pregnant mares and/or neurological disease in adult horses. As EHV-1 comes from a family of viruses that includes the human cold sore virus, it also has the ability to remain hidden within horses once they are infected (called latent infections), usually early in life, and then re-emerge, usually during periods of stress. Although it is not possible to treat horses to eliminate latent EHV-1 infections and eradicate the disease, the practical prevention and control measures that have been developed to deal with EHV-1, as outlined in the Horserace Betting Levy Board (HBLB) Code of Practice, have repeatedly been shown to be effective in minimising large-scale effects of this important infection, when they inevitably occur. We urge TBA members to continue to refer to the HBLB Codes of Practice and consult their veterinary surgeons to optimise practical biosecurity and disease prevention measures as well as promptly investigating any disease incidents, such as abortion or neurological disease.

• The HBLB Codes of Practice can be found here: http://codes.hblb.org.uk/
• The Codes of Practice are also available as an App named EquiBioSafe for Apple and Android phones