A LEADING parasitologist has warned cattle farmers to take appropriate steps to protect their stock from midges in order to lessen the risks of Schmallenberg Virus (SBV) infection.

Independent parasitologist and entomologist Dr Peter Bates said midge control during breeding times and pregnancy was highly recommended, and there was a strong case for the use of anti-fly compounds in pregnant animals earlier in the year in order to reduce midge populations.

“This is a brand-new disease and we have a lot more to learn about it. We are becoming more certain it is carried by midges, so at the moment the only control we have is the control of midges as the disease vector,” he said. “It is likely to be 18 months to two years, or longer, before we see a vaccine being produced and marketed.

“If the cow is pregnant we know what happens in terms of foetal deformities, but we don’t know what is happening to the animals outside this period. There is evidence that when a non-pregnant animal is bitten it will acquire immunity therefore midge control may not be necessary.

“However, just prior to AI or service from a bull it would be worth treating; this would then help prevent stock being bitten and contracting SBV at this critical time.

“Anti-midge products, containing synthetic pyrethroids (SPs), kill as well as repel so it is a good idea to treat the whole herd as this will reduce the midge population,” he said.

“For pregnant stock, I would recommend dosing in April and throughout pregnancy; this will help protect the foetus from the effects of SBV as well as help kill the midges that have emerged from overwintering larvae, so stopping them breeding to produce larger populations in the summer,” he added.

Thomas Tiley, a vet with Novartis Animal Health, said the use of a product such as Flypor, which contains the active permethrin, has shown in-vitro activity against midges and can be repeated at four week intervals in cattle.

“Because of the geographic spread and virus type, midges are the main suspect as the disease vector for Schmallenberg virus,” he said.

“As the effects on newborn animals can be devastating there is certainly a strong argument in favour of steps to reduce midge exposure during pregnancy. Equally, any reduction in the midge population earlier in the year may bring benefits later on when midges come out in force.

“The virus is known to reduce milk yield and cause diarrhoea and fever in cattle, and we have seen numerous stillbirths and deformities in sheep. Schmallenberg virus could have serious implications for farming in the UK, so it is well worth taking the appropriate precautions.

“Using anti-fly products in cattle can also have benefits across the board for preventing other diseases that are carried by insects such as New Forest Eye or Summer Mastitis,” he added.