MSD Animal Health has said that it’s “impossible” to prevent the spread of orf without vaccinating both ewes and lambs.

It’s been a particularity rough year for sheep farmers where orf is concerned, but the animal health products supplier says that steps can be taken to control the spread of the disease in your flock.

MSD is urging farmers to vaccinate their ewes “well before” they’re housed for lambing, with the company’s veterinary adviser Stephanie Small saying: “It is impossible to prevent the spread of orf from lamb to ewe and back again without vaccinating both parties.”

Tips for orf vaccination:

  • Only use the vaccine in flocks with confirmed cases of the disease;
  • Do not vaccinate pregnant ewes less than seven weeks before housing or lambing, in order to allow immunity to build up;
  • Ewes require an annual boost of the vaccination;
  • Watch for pustules developing after 7-10 days, which will confirm the vaccination has taken;
  • Always wear gloves while handling the vaccine;
  • Lambs must be vaccinated from one-day-old.

“For example, a recent study suggests there is an 82% chance that the mother of a lamb with orf will have the disease on her udder or teats,” she added.

MSD points out that, while the physical symptoms of orf are easy to spot, the virus can exist unnoticed in the general environment for many months in cold, dry conditions.

Even for sheep that have recovered from the disease, the virus can continue to live in their wool, so only focusing on lambs is not good enough, according to MSD.