Bluetongue is a viral disease which affects ruminants (such as cattle, sheep, goats and deer) and camelids (such as llamas and alpacas). Although Ireland is free of bluetongue, it is present in many European countries.
An outbreak in Ireland would pose a serious threat to the livestock industry here.
The virus is spread by midges which are most active from April to November, therefore, increased vigilance is essential at this time of the year.
What is bluetongue and how is it transmitted?
Bluetongue is caused by the bluetongue virus (BTV) which has 27 known different serotypes, several of which are circulating in Europe. The disease does not affect humans or pose a risk to food safety.
BTV is primarily spread by midges feeding off the blood of an infected animal and then transferring the virus to another animal by biting them.
The Culicoides species of midges capable of spreading the virus are found in Ireland.
Wind dispersal of infected midges can potentially spread the disease over long distances. Weather conditions occasionally favour the wind-borne distribution of midges from continental Europe to Ireland.
The virus can also be spread through biological products such as blood, or germinal products such as semen or embryos.
Infected pregnant animals can pass the virus to their offspring in the womb; these animals are a particularly high-risk group for introducing the virus into Ireland.
What symptoms would an infected animal be likely to show?
Susceptible species display clinical signs of the disease to varying degrees, which can range from inapparent to severe.
Clinical signs in sheep are often severe.
Outbreaks in previously unaffected countries have resulted in mortality rates as high as 70% in affected sheep.
Infected cattle and goats tend to show less severe clinical signs and can often carry the disease without showing any signs of illness. Infected animals that do not show obvious disease can act as hidden carriers of the virus causing further spread of the virus.
Clinical signs vary from animal to animal and may include: swelling of the head, respiratory distress, drooling, reddening of tissue surrounding the eyes, sores and crusts on the face, mouth and teats, discharge from the eyes and nose, loss of appetite, drop in milk yield and abortion.
How can we keep bluetongue out of Ireland?
The importation of an asymptomatic infected animal represents the most significant risk factor for the introduction of BTV into Ireland.
Animals originating from bluetongue-affected areas are vaccinated against the disease. However, no vaccine is 100% effective for all animals. Therefore, it is important that risk mitigating actions are taken.
All bluetongue susceptible animals imported from mainland Europe, must be tested for the disease following their arrival to Ireland. This testing is carried out by the Department of Agriculture Food and the Marine, for the protection of the national herd and flock.
If you are considering importing animals susceptible to bluetongue, you should ask yourself the following:
Is import of the animals really necessary?
It may be possible for the genetic change or gain that you are looking for to be obtained locally or in a bluetongue–free country. If the import is necessary, then every effort should be made to only import susceptible animals during the lower risk season for midge activity (December to March).
Consult with your private veterinary practitioner before purchasing animals in other countries for advice on pre-import tests
If an outbreak of bluetongue were to occur in Ireland during the midge season, control and eradication of the disease could be more difficult than during the lower risk season for midge activity.
Are the animals pregnant?
Infected pregnant animals can pass the virus to their unborn offspring in the womb. Presence of the virus may not be detected until the offspring is born.
These animals pose an even higher risk than non-pregnant animals of inadvertently introducing BTV into the country. If the import is necessary, consider breeding the animal in Ireland after importation.
Am I buying from a reputable source?
Consult with your private veterinary practitioner before purchasing animals in other countries for advice on pre-import tests to prevent introduction of diseases into your herd, flock or country. Obtain proof of vaccination and request pre-export test results for any relevant diseases before you import.
Contact your local regional veterinary office (RVO) for advice on import certification requirements.
What should I do when the animals arrive in Ireland?
Isolate the imported animals in a clean shed away from the rest of the herd or flock.
Check that the animals satisfy identification and certification requirements and that they appear healthy. Ensure that they have access to clean dry bedding, feed and water.
Contact your vet without delay if any animals appear unwell.
Contact your local RVO immediately once the animals arrive to arrange the post-import checks for diseases.
Early detection of BTV is of key importance in controlling any potential outbreak.
Bluetongue is a notifiable disease, which means that there is a legal obligation for any suspect case to be reported to the Department of Agriculture, Food and the Marine.
If you suspect the presence of bluetongue on your holding, contact your local RVO without delay (during office hours) or the national disease emergency hotline on 01-492 8026 (outside office hours).
An outbreak of bluetongue in Ireland would result in: