A severe case of blowfly strike has been reported in Dorset in which 50% of a lamb group have been hit by the disease, according to an interactive map chronicling the UK's first blowfly strikes of 2018.
The interactive map, produced by Elanco Animal Health and NADIS (National Animal Disease Information Service), highlights areas hit with blowfly strike in real-time.
It aims to deliver the most comprehensive and immediate warning system for farmers, vets and industry professionals.
The first reported incidents were in Hampshire, before spreading across Devon, West Sussex, and Buckinghamshire. Particularly severe cases include a flock in Dorset, in which 50% of a lamb group have been hit by blowfly strike. Latest reports are in northern England and some initial cases in Scotland.
The NADIS and Elanco blowfly risk forecast suggests that weather conditions from southern England and Wales to the Midlands mean that flies are now active, and females are laying eggs that result in serious welfare and productivity issues.
Richard Wall, Professor of Zoology at Bristol University said the timing and severity of blowfly strike is strongly influenced by the weather.
“This is a reminder to farmers that now is the time to act for early prevention. Delaying treatment not only costs the farm but risks the welfare and productivity of the flock. Strike can develop very quickly, with the first maggots appearing within 12 hours of eggs being laid. Don’t get caught out,” Mr Wall said.
Costs of inaction
Fiona Hutchings, Technical Vet at Elanco said the costs of inaction when it comes to blowfly strike far outweigh the costs of protection.
“With 99% of farmers having suffered financial losses as a result of blowfly strike, the potential impact on your flock simply isn’t worth the risk,” Ms Hutchings said.
“Farms need to take control — and take control early — by using a preventative IGR product with full fleece protection.”
Mrs Hutchings said that just monitoring symptoms is not an effective strategy. “By the time symptoms show themselves, it’s often too late. It’s easy to overlook even one struck sheep, and blowfly strike can cause huge damage in very little time. In addition, using protection early reduces risk later in the season by ensuring a much lower fly count as the season progresses.”
Blowfly strike is a major economic concern for farmers with considerable prevention costs involved for all at-risk sheep. Sheep affected with blowfly strike have disrupted grazing patterns and rapidly lose weight especially if untreated for several days. Death occurs in neglected sheep.