Virus guidelines issued amid vaccine shortage
“Technical problems” at the only factory in the country producing the vaccine against louping ill will mean that it will not be available this season and possibly next.
In the absence of being able to vaccinate to control this problem, a “best practice set of guidelines” has been published to help sheep producers prevent the spread of this viral disease, which causes neurological disorders in infected stock. The disease is transmitted by ticks and infected sheep suffer tremors and throw their heads back over their shoulders.
One of the authors of the report, Dr Mara Rocchi, of the Moredun Research Institute, outside Edinburgh, said the guideline document was an attempt to fill the gap caused by the temporary disappearance of the vaccine.
Moredun researchers first came up with a vaccine to control the disease in the 1930s and for the next half-century the institute made it on their premises. However, in the 1980s a commercial company took over the work
0 Louping ill virus is transmitted among sheep by ticks and continued to do so until last year when problems arose with the manufacturing process.
Dr Rocchi described the breakdown in production as a “technical problem”, adding that, while the company was based in the UK, the vaccine was manufactured abroad.
She said: “We wanted to put practical information down to see what can be done on farm in the absence of the vaccine.”
Louping ill occurs in parts of the country such as grouse moors where ticks live. Sheep that have either been exposed to infected ticks or have previously been vaccinated tend to be immune, as do lambs born from such sheep, especially if they have been fed colostrum.
In fact, sufficient colostrum fed in the early years from hefted ewes can provide good future protection from the virus.
As regards farm biosecurity against louping ill virus, the advice from Dr Rocchi and her colleagues is “if you don’t have it, don’t buy it in”.
Finding out if bought in sheep have previously been exposed to ticks is also recommended, as is good hygiene in sheep sheds.