A NATIONWIDE shortage of the vaccine against the Louping Ill Virus (LIV) will come as grave news to hill farmers, particularly in the Western regions of Scotland where louping ill is most prevalent.

Cases of LIV, which is transmitted by ticks and is principally seen in sheep and red grouse, have increased, not helped by global warming and the ability of the ticks to adapt to the changing Scottish climates. Ticks become infected when they feed on a host animal with high levels of LIV in their blood and these high levels only occur in sheep and grouse for a maximum of five days following infection.

The vaccine, which was successfully developed and initially produced at Moredun in the 1930s, has become temporarily unavailable. Dr Mara Rocchi, leading the research at Moredun, commented: “The vaccine is so important to sheep farmers especially those living in hilly areas of Scotland where cases of the virus are most prevalent. Recently we were made aware that the vaccine might not be available for 2018 or even 2019. In the absence of a vaccine, the institute are providing guidelines to farmers on the management of their sheep flocks.

“The main messages we are delivering through our guidelines includes liaising with your vet to develop a working tick control plan for your individual farm and circumstances, to how to best manage unprotected lambs and naïve sheep. The document also includes advice on treatments for tick control, including in young lambs and tups, along with factors impacting on the efficacy of tick control treatments, biosecurity tips and wildlife and habitat management.”

Current mortality rates in flocks where cases of the virus have been identified stand at 5-10% of the whole flock, with 50% of infected sheep showing symptoms of the virus dying. The LIV vaccine is manufactured outwith the UK as laboratories here don’t meet the quality standards needed to carry out the necessary research. Any stocks of the vaccine which are still in supply have been allocated to vets in areas of the UK where louping ill is most prevalent. However, the message being given to farmers is to manage their flocks as best they can without reliance on the vaccine, as manufacturing delays look set to continue for years to come.