As many of you are no doubt aware, thanks to the constant stream of APHA emails, Bluetongue (BTV-3) has returned alongside the start of peak midge season. This was a fairly predictable outcome given the narrow escape we had last year, and it popped up earlier in the year than last time. This may potentially give the virus more time to circulate further across the country before it starts to get cold enough that the midges become less effective carriers, though hopefully the surveillance testing and movement restrictions in the high-risk areas may slow this down.

As with last year, most cases of BTV-3 this autumn have been found in the South East in Essex, Kent, East Sussex, Suffolk and Norfolk. However, surprisingly, there was a further case detected through surveillance in Yorkshire, so it is important for all of us to remain vigilant for symptoms, even whilst there are no current cases on our doorstep (as of 16/9/24).

This disease affects all ruminants, such as cattle, sheep, goats, camelids, and deer. After infection with the virus via infected midge bites, the severity can vary from unnoticeable to death – this varies between species (disease tends to be more severe in sheep than cattle and goats) but also between individuals.

All ruminant keepers must remain vigilant for any of the following symptoms this coming autumn and winter and call us or the APHA to discuss if you are suspicious.

• Fever
• Depression, trouble breathing or panting with excessive salivation
• Nasal discharge which will start clear and progress to a snottier discharge, may crust around the nostrils
• Reddening around the eyes, nostrils and mouth.
• Swelling of the muzzle, lips, eyelids, ears or tongue. This may then progress to a tongue that is bluish in colour which may protrude out of the mouth – this is not present in every case and more likely to be seen in sheep.
• Ulceration around the lips, tongue and inside the mouth.
• Lameness, usually of multiple feet. Usually accompanied with reddening and swelling of the coronary band (where the skin/hair meets the hoof), can look similar to CODD in sheep but affecting multiple feet. This can be extremely painful affecting multiple feet, which may result in sheep or cattle standing in a similar stance to a laminitic pony – with back arched and feet tucked in under them.
• You may also be able to spot a reddening of the skin in the armpits and groin of affected sheep.
• Abortions, stillbirths, weak lambs/calves, poor reproductive performance, congenital defects causing neurological symptoms.
• General emaciation, production losses, poor thrift and wool loss may be seen in sheep.
• In cattle, the symptoms are largely the same as those listed above for sheep, though typically not as severe. Symptoms that tend to be more cattle-specific would include teat and vulva lesions, poor fertility and reduced milk yield.

In terms of prevention, we are not quite as defenseless as we were this time last year, however the vaccines may only be feasible for highly valuable pedigree stock. We have recently been informed that it is possible to apply for a license to use one of three BTV-3 vaccines. Bear in mind that these vaccines, for now, are mostly available for use within the High-Risk counties to manage supply towards where it is needed most, though it may be possible to apply for use under a specific license through the APHA shortly in discussion with your vet. These vaccines do not prevent infection or transmission of the virus, though they should reduce severity of symptoms and reduce the risk of dying – think of it like the COVID vaccine.

Think very carefully about sourcing animals from the South East of England. Any ruminants being moved out of the Restricted Zone must be done under licence, following a negative blood test. However, within 6-10 days of the movement, you are required to do post-movement testing on that animal and will be under movement restrictions until you do. It is the responsibility of the keeper to organize this with UKFarmcare. You also cannot currently import ruminants from countries affected with the disease such as France, The Netherlands, Germany, Denmark and now Norway – all of whom have seen cases this summer as well. Ask for pre-movement testing on any animals being imported from other parts of Europe.

Unfortunately, there is no evidence behind any insect repellents preventing the spread of Bluetongue, though they should be being used anyway this time of year for general fly control.

Aside from that, it comes down to management practices in order to try and reduce midge exposure. Midges are particularly fond of fields with good tree cover, boggy areas and streams and that are sheltered from the wind. Midges struggle to fly with a crosswind so if available, try to graze more exposed hillsides away from natural water sources if BTV-3 does creep closer. Alternatively, housing sheep or cattle and installing very fine midge netting over all inlets to the shed can also help – especially if you can set up large stock fans to keep a good crosswind going across the shed. Obviously, these are measures that are likely to only be practical for small groups of very valuable animals. As midges are most active at dusk and dawn, consider housing overnight, and letting out during the day as a compromise, though still riskier than full-time housing.

As Bluetongue is a notifiable disease, if you are at all suspicious of any of the above symptoms, you must call us or the APHA (on 03000 200301) to discuss. You can, of course, call for any other questions or advice on 01823 662286. Further BTV-3 vaccine product information is also available on request.