Bluetongue is a viral disease that affects sheep, cows, goats, deer and camelids (such as llamas and alpacas). The strain of Bluetongue that is causing problems in the UK is BTV3 and below details the top clinical signs.
BTV3 is spread by biting midges and numerous cases have been confirmed with restriction zones covering large parts of Eastern England. It has been brought across from Europe by wind-borne infected midges. Other high risk areas for infection include the South Coast of England (from Cornwall eastwards). It is not advisable to buy in stock from any of these areas at this time.
Blue tongue is a notifiable disease – if you suspect a case you must report it to APHA – in Wales 03003 038268. If your private or APHA vet suspect BTV, then the farm will be placed under movement restrictions. If the case is confirmed, then in the early stages of an outbreak in this region, compulsory culling may be considered. Once the virus is circulating in an area, then compulsory slaughter will cease but movement restrictions in some form will still apply.
Signs in cattle (most common first)
- Depression
- Lameness
- Ulceration (oral and nose lesions)
- Red membranes (eg teats)
- Conjunctivitis (eye discharge/redness)
- Crusting around nasal area
- Redness above the hoof (coronitis)
- Fever
- Nasal discharge/salivation
Signs in sheep (most common first)
- Nasal discharge
- Depression
- Swollen face
- Crusting around mouth/nose
- Excess salivation
- Red membranes
- Inappetence
- Ulceration of mouth and nose
- Lameness/reluctance to move
Vaccination and prevention
Once an animal is infected and showing clinical signs, painkillers have been found to be useful in alleviating the symptoms. Secondary complications are common, including pneumonia, hoof damage/defects, sloughing of dead tissue, joint infections and other secondary infections.
The Government has authorised the use of vaccines active against BTV serotype 3 in England (under certain conditions). These vaccines only reduce the clinical signs experienced, they do not prevent an animal becoming infected or infectious. They will be used initially in the high risk areas. Contact your private vet if you are interested in following this up.
Use of insecticide as a prevention on livestock doesn’t seem to help much. Housing animals at dawn and dusk when midges are most active, can reduce the chances of infection.
The virus development in midges can only occur when the temperature is above 12C so let’s hope some cooler autumnal weather arrives.
