Bluetongue case study - Ian May, North Devon
15th August 2026
Please find a case study below from Ian May, a sheep farmer from North Molton, North Devon. Ian farms 500 ewes, 120 shearlings, 10 rams and 750 lambs. This case study is written by Ian, from his own perspective.
As we are in the middle of the North Devon bluetongue hotspot, I thought it would be useful to outline how the disease has affected our farm and how our thoughts on diagnosis, treatment and vaccination have evolved over the past few weeks.
Our ewes and rams were last vaccinated in March 2025. As more cases were reported nearby in late July 2026, we decided to revaccinate all our ewes and rams, along with our shearling replacements. At the time, with little experience of the disease, we felt this was a pragmatic course of action, given the time required to vaccinate and the associated cost.
Our first suspected case of bluetongue was seen in a lamb on 29th July. The case is still awaiting confirmation from APHA, but the lamb showed characteristic clinical signs, including lethargy, a swollen nose and drooling.
Following this initial case, we found several other lambs showing similar symptoms. On veterinary advice, these lambs were treated to support their recovery.
As the number of affected lambs increased rapidly, we decided to also vaccinate our home-bred ewe lambs and the smaller proportion of lambs we intend to sell for meat. We felt these were the animals most likely to remain on the farm for the longest and therefore those that would benefit most from vaccination.
As the vaccine can take up to 30 days to provide full protection, we have continued to see clinical signs in both vaccinated and unvaccinated lambs. However, I have not had any cases in my ewes or rams.
At present, we are treating between five and 10 lambs a day. Some make a swift recovery, while others require two or three treatments before showing a response. To date, I have probably treated at least 60 of our 750 lambs.
Although our mortality has been relatively low, at around 8–10 lambs, compared with others who have been less fortunate, the lambs affected by bluetongue can take a long time to fully recover. They will also require careful management to ensure they reach their finished weight.
The additional work and stress for both us and the livestock, caused by regularly gathering and treating affected lambs, together with the visible decline in their condition, has changed our thinking. I have now decided to press on and vaccinate all the sheep on the farm.
While the cost of vaccination is not insignificant, our experience so far has shown that the alternative cost of treatment, additional labour and lost productivity can easily outweigh the cost of the vaccine.
Some key thoughts and insights I’ve gained over the past few weeks include:
- The on-farm experience of the disease varies greatly from farm to farm. Those who have had no exposure to the vaccine are fairing worst. Some farms are seeing at least 10% losses across the flock.
- All flocks are experiencing some losses, our local fallen stock company is currently collecting five times as many dead animals as usual. This includes an increase in cattle mortality.
- Confounding factors such as sheep condition, access to water, grass availability and worm burden (including haemonchus) also play an important part in the level of infection and mortality.
- Symptoms can be subtle at first and misdiagnosed if you’re not looking for them.
- The long-term implications of infection on ewe and ram fertility are yet to be fully realised.
- The current outbreak is growing quickly and is far ahead of the confirmed cases, significant numbers of potential cases are already in the majority of Somerset and North Dorset.
- Whilst the South West is being affected most dramatically at the moment, cases are also occurring throughout the rest of the country and could expand rapidly. All livestock keepers need to be vigilant and plan how they intend to manage it.
