Beware orf in unvaccinated lambs at grass
MILTON KEYNES, UK, 10 June 2016 – Shepherds are being urged to remain vigilant for signs of orf in growing lambs this grazing season, particularly if pastures are prone to thistles and the animals have not yet been vaccinated.
“Orf is a continuous threat and is quite often seen in older lambs that have picked up skin abrasions while grazing,” points out MSD Animal Health technical manager John Atkinson MRCVS.
“Orf is caused by a virus, and before it can cause disease it needs to get into the surface of the skin. This usually happens through cuts and scratches, no matter how small. One of the most common causes for these are thistles, which can easily break the skin around the mouth as the lamb grazes, and if the orf virus happens to be present on the skin, it can then easily infect the animal and cause disease.
“It is not only thistles that you need to pay attention to; nettles, brambles, rough grazing or cut foliage from hedge trimming could also lead to skin damage and subsequent orf outbreaks.”
Mr Atkinson adds that if the disease does break out at grass – and if you’ve seen orf before there’s every likelihood that it could, simply because the virus can survive in the environment for many years – any infected lambs are less likely to finish on time. A recent study found lambs affected by orf to be 10% lighter than disease-free animals after an outbreak1.
He also says that orf infections in any young sucking lambs can quickly spread to ewes, causing sore teats and mastitis, which can be very serious, even fatal.
SCABIVAX® FORTE (the only vaccine against orf, from MSD Animal Health) is available from the vet, and any farmers who have seen the disease in their sheep before, but not yet vaccinated lambs this season, should contact their practice as soon as possible.
“With the proven and costly impact orf can have on lamb growth rates, it’s certainly well worth vaccinating to protect productivity, particularly if your finishing lambs are currently on any rough grazing,” Mr Atkinson says.