TBA VETERINARY NOTICE: Pre-Season Updates on Equine Infectious Diseases
With the 2026 breeding season fast approaching the TBA would like to take the opportunity to provide some important equine infectious disease updates, and to draw attention to some key points related to maintaining the highest standards of equine health and wellbeing on stud farms.
West Nile Virus (WNV): During a January meeting with Defra, it was reported that a dead seabird recently found on the south coast of England had tested positive for WNV antibodies (a virus transmitted by biting insects and which causes encephalomyelitis, i.e. inflammation of the brain and spinal cord). As a consequence, the risk level of the disease has been moved up to two (on a four-point scale). The risk of infection here in the UK is still considered relatively low, but continued vigilance is advised. Equine vaccines are available in Britain (Equip WNV and Proteq West Nile) and are especially recommended for administration to those thoroughbreds who may be travelling (permanently or temporarily) to affected regions in mainland Europe.
Equine Viral Arteritis (EVA): Further to the TBA communication circulated to members on 3rd November (available here: https://www.thetba.co.uk/resource/publication-of-2026-nsfa-breeding-regulations-and-eva-health-testing-amendments.html), formal approval of biosecurity protocols for the use of the live vaccine, Arvac has subsequently been received from Defra and the Veterinary Medicines Directorate (VMD). This would expedite procedures to obtain an import licence for Arvac, in the event of any future disruptions in supply of Artervac. The TBA worked with the VMD to reduce the quarantine zone post primary vaccination from 100 metres to 50 metres, which would be workable for a higher number of British stallion studs.
Equine Herpesvirus (EHV-1) and Equine Influenza (EI) in France: Following the increasing number of EI outbreaks in France since the beginning of autumn (primarily affecting Trotters) and the circulation of EHV-1 since the beginning of the year, RESPE has recently called for heightened vigilance regarding these two diseases (regular monitoring of temperatures) and recommended the implementation of strict biosecurity measures for all horses being imported from France, especially those who may have been in contact with Trotters.
Cervical Swabs: Breeders are reminded of the importance of testing cervical swabs via culture, as well as by rapid PCR. Whilst PCR testing can identify (or rule out) the presence of specific venereal bacterial pathogens, a bacterial culture is required to detect other (non-venereal) strains. Mares may have uterine infections that would go undetected by PCR, which will require treatment in order to optimise their chances of conception and reduce the risk of pregnancy loss.
African Horse Sickness (AHS): AHS is the third ranked animal disease threat on the UK’s National Risk Register. Defra recently advised that their report (following an audit in South Africa) should be available soon. Draft protocols for managing a possible future case of AHS in Britain would also be shared by Defra at that time. Once available, both reports will be carefully reviewed by the TBA and broader equine industry. As horses may now be imported direct from South Africa into Europe, breeders should check the Country of origin of any thoroughbreds arriving on their farms from mainland Europe.
Foal Crop Traceability: Detailed studies of two British-bred foal crops have now been performed, in an effort to understand pathways, outcomes and performance metrics of thoroughbreds whilst in the industry and beyond. The TBA recognises that closing the data gaps that exist within the thoroughbred industry is vital in building the trust of the general public and in maintaining the social licence to operate. Breeders are reminded of the importance of completing transfer of ownership records and deceased reporting with the General Stud Book. Please also ensure that broodmare registration is completed prior to any coverings taking place. Equine Influenza (‘flu’) vaccinations for youngstock (foals and yearlings) should also be uploaded to the Vaccination App. These data touchpoints provide the industry with greater real-time insight of the whereabouts of the British thoroughbred population, equipping the sector with traceability statistics to shape positive and pro-active equine welfare communications.
HBLB International Codes of Practice: (can be viewed here: https://codes.hblb.org.uk/ or a hard copy is available by request from the TBA). The marvellous record of equine infectious disease control and prevention across the thoroughbred industry has been reliant on close adherence to the Codes of Practice. Trust, candor and cooperation are essential. The NSFA Breeding Regulations (2026) (which can be viewed here: https://nsfa.org.uk/) were updated in advance of this breeding season to ensure that in the event of an inconclusive EVA ELISA test result, the mare is not accepted for covering until negative or stable/declining paired positive Virus Neutralisation Test results are obtained. Please do permit your veterinary surgeon to anonymously report cases of infectious disease outbreak, such as EHV-1 pregnancy loss/neonatal foal death, to the International Collating Centre (ICC) – you may report by region rather than county if this is preferrable in maintaining anonymity.
A pre-season reminder on biosecurity protocols presented by Billy Fehin MRCVS (Rossdales) can be viewed here: https://www.youtube.com/watch?v=YmdcGzOd1c4
Thank you to those breeders who have already paid the new TBA Equine Welfare Levy, whilst registering their January-born foals. The £60 levy payment will enable the TBA to continue vital work around equine infectious disease control and prevention; biosecurity and border controls; vaccine and medication availability and stewardship; continued investment in and communication of veterinary research; lifetime traceability of the thoroughbred; and genetic diversity; as well as making a breeding sector contribution to the RoR funding model, which will underpin their delivery of aftercare initiatives and safety net frameworks for all horses bred to race.