Bluetongue – what it is and what you need to know

Cases of bluetongue have been on the rise since 2023, with a significant jump in cases since the sweltering heat of 2026. Our livestock advisor Dr Alison Bond lays out the facts.

Date published: 29 Oct 2026

Author: Alison Bond

Farming

Bluetongue virus (BTV) has been a significant issue affecting sheep and cattle farmers this year. Many have experienced significant loss of animals and incurred major cost, labour and emotional impact from trying to care for sick animals and nurse them through the disease. This has impacted prices and supplies of sheep through the meat trade [1]. The substantial effects of the virus on fertility have affected breeding decisions and timing that could have a knock-on effect into the availability of next year’s lamb [2].

Rise in cases

Since 2023, bluetongue has begun to circulate in ruminants and camelids. The first cases of BTV infection for fifteen years were detected in November that year and have slowly risen from 126 cases in 2023/2024 to 348 in the 2025/2026 season. This summer’s temperatures have been optimal for the virus. We’ve seen a jump in cases to over 3424 so far (correct on 19 Oct 2026) recorded in England, Wales and Scotland, with BTV-3 being the main strain detected. There have been no cases of BTV-8 confirmed this year (correct on 19 Oct) [3].

BTV diagnosis

Initially this rapid expansion of cases resulted in insufficient laboratory capacity to process the sudden large number of samples. This led to a delay in confirmation of suspected cases, causing stress and worry amongst farmers waiting for results. Bluetongue is a notifiable disease so any suspected cases must be reported and tested. Additional laboratory resource have now been allocated [4]. Hopefully this will ensure the stress of delayed testing won’t be repeated in the future. Where symptoms are straightforward and clear, vets can now diagnose and confirm a case from symptoms alone [5].

It’s important for sheep and cattle farmers in England to remember they can apply for a vet visit (funded by the government) through the Animal Health and Welfare Pathway. The vet can check animals for signs of disease and advise on bluetongue risks and how to reduce them [6]. Where there are suspected cases, the lab analysis fees for three samples are covered by the Animal and Plant Health Agency (APHA) for those farmers who are eligible, but they will need to pay for their vet to take the samples. For farmers in Wales and Scotland, after reporting a suspected case, the cost of taking samples and laboratory analysis is covered [7].

Impact of heat stress

This year’s prolonged heatwave has certainly exacerbated the effect of bluetongue. Infected animals may have a high temperature, respiratory challenges and a reduced feed intake after initial infection, and high environmental temperatures make it more difficult for them to regulate body temperature. It can also make detecting the disease more difficult as animals may be exhibiting the same symptoms for either, or both, heat stress and bluetongue. Making sure there is enough shade and air flow around animals, providing plenty of water and minimising handling are all important actions, not just in managing the symptoms of bluetongue, but for animal wellbeing in general [8].

Fertility in sheep and cattle

Bluetongue infection reduces fertility, impairing semen quality and causing temporary infertility in rams. Effects on ram sperm quality are reported as being severe but temporary (63-138 days post infection) [2]. Bluetongue infection also causes abortions, foetal abnormalities and stillbirths. Affected cattle herds also see increased fertility problems and abortion. There is no evidence that the vaccine itself causes fertility problems [9]. It's the disease that causes the fertility problems.

This effect on fertility makes the timing of infection significant as it may mean delaying the breeding season to allow recovery and ensure good conception rates. This could impact the timing of the supply of lambs in the early months of next year, with a later start to lambing in some areas.

For some farmers the loss of livestock to the virus has reduced flock/herd size. If you are an organic farmer whose livestock numbers have been affected, you may find the Organic Marketplace a useful place for organic stock replacements. We're also aware that seeing your animals ill with disease is distressing, and the physical and emotional impact of caring for sick animals is huge. Always remember there are a number of farmer support organisations available to help anyone who is struggling with the challenging impacts of this.

Three white and brown cattle, laying in long grass as sun bursts through the leaves of a low tree canopy above them.

Vaccination

Vaccination remains the main method of protecting livestock if your herd or flock are likely to be at risk. Three vaccines are available for BTV-3 (the predominant strain each year so far) which your vet can prescribe. It is important to note that the vaccine for BTV-3 does not provide cover for BTV-8 or any other serotypes. AHDB have created cost calculators and a decision-making tool to help farmers make an informed decision with their vet [10].

Whether, and when, to vaccinate is a decision that should be taken with your vet. Protective immunity develops approximately 3 weeks post vaccination and lasts for approximately 12 months [11]. For Soil Association Certification clients, if vaccination is considered the best course of action, please continue to administer them without the need for prior permission, but add this to your herd/flock health plan ready for your next inspection.

Useful information

Keep up to date with the number of confirmed cases and other relevant information on the government website. When moving livestock, to ensure compliance with the legal requirements in the movement restriction zones, Ruminant Health and Welfare and AHDB have developed the Bluetongue Movements Checker tool to help farmers in England, Wales and Scotland keep up to date as those zones change during the year.

Next year

Looking ahead, taking veterinary advice, ordering vaccines early and ensuring livestock are vaccinated and protected before the start of the midge season in your area is recommended. Midges are active between spring and early winter, with onward transmission greatest during early summer and autumn, usually peaking during September. Aim to have livestock fully protected during spring to ensure the best protection for your stock and your business.

Organisations that can provide support:

Soil Association clients, please always reach out to the Producer Certification team or Farming and Land Use Advisor team to chat through any challenges you are facing:

Producer Certification: 0117 914 2412

Farming & Land Use Team: 0117 314 5100

RABI - the Farmers Charity: rabi.org.uk; 0800 188 4444

Addington Fund: addingtonfund.org.uk; 01926 620135

The Farming Community Network: fcn.org.uk; 03000 111 999

Ruminant Health and Welfare and AHDB have developed the Bluetongue Movements Checker tool to help farmers in England, Wales and Scotland keep up to date as those zones change during the year.