Although bluetongue does not affect horses, the significant emergence of bluetongue virus-3 (BTV-3) in livestock in the Netherlands in September 2023 and its subsequent detection in Kent and Norfolk since November 2023, highlights the risk to the UK of windborne transfer of biting midge-borne orbivirus infections from mainland Europe. African horse sickness (AHS) virus is a related orbivirus that is transmitted by biting midges and would pose a highly significant threat to the UK equine industry should it emerge in Europe outside of its usual distribution in sub-Saharan Africa.
Whilst on the topic of insect borne viral diseases, late autumn 2023 again saw cases of West Nile virus (WNV) neurological disease confirmed in more northerly parts of Europe than has traditionally been the case. Horses affected by WNV were reported in northern Germany, including close to the Netherlands border into October and along the Atlantic coast in France into November – whilst it is now hoped that the colder winter weather has arrested the transmission of WNV through the bites of its mosquito vectors, UK equine vets should remain alert to the emergence of this disease when the warmer weather returns.
Further details on the emergence of WNV in Europe and the UK’s surveillance efforts, including details of steps to be taken by vets who may suspect the disease or want to test to exclude it, are available in a focus article in the equine quarterly disease surveillance report from the first quarter of 2020. The article is a reproduction of a Surveillance Focus by members of Defra’s Veterinary Exotic Notifiable Diseases Unit that appeared in the Veterinary Record in September 2019. The latest details on testing to exclude WNV in horses are available here.
Access the Equine Infectious Disease Surveillance website.
By Richard Newton, Equine Infectious Disease Surveillance (EIDS) Group