Bluetongue: Advice to farmers
Bluetongue - Complacency Costs!
Watch Defra’s Bluetongue video outlining why farmers can’t afford to be complacent about Bluetongue in 2009, featuring farmer Robert Law and Deputy Chief Vet Alick Simmons.
Full transcript of the video (PDF 50KB)
Further advice
- What can I do?
- Definition
- How to spot the disease (clinical signs)
- How to report the disease
- Guidance on the midge mitigation measures
- How is Bluetongue controlled
- Current Bluetongue Protection Zone
- Movement licences for slaughter and to live
What can I do?
Don’t hesitate, vaccinate...
Vaccination is the only effective way for individuals to protect the welfare of their animals and their own livelihood. The nature of this disease is such that keepers cannot rely on their neighbours’ vaccination: midges can be carried by winds and by human activity. The only sure way is to vaccinate your own animals.
You can order vaccine in 20ml, 50ml and 100ml bottles from your vet although some bottle sizes may be more readily available than others as supply proportions vary over time. More information on vaccination is available here.
Remain vigilant...
To remain vigilant for Bluetongue you should inspect your stock, particularly focusing on the mucous linings, (lining of the mouth and nose) and the coronary band (where the hoof stops and the skin starts), and; if you suspect one of your animals has Bluetongue, it is vital to report it as early as possible. Telephone your nearest Animal Health Office immediately or call the Defra helpline on: 08459 33 55 77 between 9am - 5pm, 5 days a week.
Definition
Bluetongue is a disease of animals affecting all ruminants, including sheep, cattle, deer, goats and camelids (camels, llamas, alpacas, guanaco and vicuña). Horses and pigs are not susceptible species. The disease is caused by a virus spread by certain types of biting midges.
How to spot the disease (Clinical signs)
Clinical signs can vary between species. Although symptoms are generally more severe in sheep, cattle can occasionally show signs of disease. Cattle are important in epidemiology of Bluetongue as they act as an often silent source of Bluetongue Virus (BTV) – a reservoir for disease and keep the infection circulating. It is important to be vigilant, especially in the case of sheep. If you suspect any signs of the disease you must report this immediately to your local Animal Health Office.
Leaflet: Bluetongue - Guidance for livestock keepers (PDF 1MB)
Photos: Photos of clinical signs.
Clinical signs in sheep:
- Eye and nasal discharges
- Drooling as a result of ulcerations in the mouth
- High body temperature
- Swelling of the mouth, head and neck
- Lameness
- Haemorrhages into or under the skin
- Inflammation at the junction of the skin and the horn of the foot – the coronary band
- Respiratory problems – difficulty with breathing and nasal discharge
- A bluetongue is rarely a clinical sign of infection
- Deaths of sheep in a flock may reach as high as 70 per cent. Animals that survive the disease can lose condition with a reduction in meat and wool production.
Clinical signs in cattle:
It is possible that cattle will show no signs of illness, however clinical signs have included:
- Nasal discharge
- Swelling of the head and neck
- Conjunctivitis (runny eyes)
- Swelling in, and ulceration, of the mouth
- Swollen teats
- Tiredness
- Saliva drooling out of the mouth
In cattle, the disease cannot be diagnosed on clinical grounds and requires laboratory testing for confirmation.
How to report the disease
If you suspect signs of any notifiable disease, you must immediately notify your local Divisional Veterinary Manager.
Guidance on the midge mitigation measures
No one measure will prevent midges biting animals. However, the use of a combination of these measures will help reduce the risk of animals becoming infected with BTV. Culicoides breeding sites can be potentially reduced by:
- Moving dung heaps away from livestock or covering with a plastic, watertight cover
- Scraping the perimeters of heaps/slurry pits to a depth of 6-10cm (this is where the majority of larvae reside)
Housing of animals in an enclosed space (where the means are available close doors and cover entrances with mesh) during periods of peak Culicoide activity may reduce biting rates. Farmers should be aware of the midge conditions on their premises, for example bringing hill sheep into low land where midges are more prevalent would increase the risk of midges biting. No insecticides are authorised specifically to act against Culicoides.
- Deltamethrin-based compounds have performed best in tests, however, they only offer limited coverage of animals and provide 1-2 days protection at best (as do other generic repellants)
Insecticides and repellants do not entirely remove the risk of an animal contracting bluetongue and Defra recognise their use on farms does not provide a practical and cost-effective control measure against bluetongue in most cases.
Application of insecticides for short-term protection of animals transiting BTV zones, or where required for specific livestock movements (i.e. licensed moves) can be required.
- Animals and their vehicle must treated prior to travel.
- The product used should be based on a synthetic pyrethoid (eg Deltamethrin) and hold a GB marketing authorisation
- Insecticide should be used in accordance with manufacturers instructions.
Spraying at rates beyond the manufacturers instructions will not improve efficacy and increases the risk of groundwater and surface water pollution.
Synthetic pyrethoids are highly toxic to insect life in rivers and streams. Take great care not to allow these products to enter surface of groundwater. In particular, spraying vehicles on a hard stand presents particular dangers as run-off can be concentrated.
Defra do not recommend the treatment of the general environment with insecticides, as this will have little effect on midge populations and has serious environmental implications.
How is Bluetongue controlled
Background
The measures set out in legislation are aimed at preventing disease spread through, for example, restriction of animal movement and through vector control measures. Broadly, the controls can be summarised as follows:
- Veterinary investigation on suspect premises, and restrictions which include a ban on movement of susceptible animals on and off the premises.
- On confirmation that Bluetongue virus is circulating, restrictions remain in place and are extended to a zone of 20km radius around the infected premises (IP).
- Wider Zones must also be declared:
- a Protection Zone (PZ) (at least 100km radius around an IP) and a Surveillance Zone (SZ) (at least 50km in radius beyond the PZ). Together they are called the Bluetongue Restricted Zone.
- We have some flexibility in demarcating the Bluetongue Zones (with Commission agreement), but various factors such as local geography must be taken into account. The size of the Bluetongue Zones in England is based on EU legislation for control of the disease and veterinary risk assessment.
Zone descriptions
- The Restricted Zone is the overall area where restrictions apply and comprises the Surveillance Zone and the Protection Zone, and if required, the more tightly restricted disease control zone around infected premises.
- The Surveillance Zone forms the outer area of the Restricted Zone and is at least 50km wide.
- The Protection Zone forms the inner area of the Restricted Zone and is at least 100km radius surrounding infected premises.
Figure 1 shows how the Zones relate to one another.
Current Bluetongue Protection Zone
Details of the Protection Zone in force is available on the movements guidance and licences page.
Interactive map - Search by postcode to see if you are in the Protection Zone.
Movement licences
A number of movement licences are applicable to ruminants concerning their movement to slaughter and/or movement to live where the movement is from one Zone to another.
Following the change in names of the Bluetongue Zones, some Bluetongue movement licences have additional conditions. Check the licence conditions carefully to ensure you comply with them all.
Please see the movements guidance and licences page.
Will infected animals be slaughtered?
As Bluetongue is spread via vectors (i.e. midges), rather than from animal to animal, compulsory slaughter of ruminants infected with bluetongue would not normally form part of our control strategy.
Page last modified: 30 June, 2009