Tim’s take:
Every flock meets orf eventually, usually in the lambing shed, usually at the worst moment: a pen of thriving lambs one week, scabby mouths and ewes kicking off sore teats the next. It is rarely a killer and there is no cure to buy, which makes it exactly the kind of disease where knowing the shape of the thing in advance beats anything you can do once it arrives.
What orf is
Orf goes by the textbook name contagious pustular dermatitis, and NADIS is blunt about the cause: a pox virus that remains infective for many months in dried scabs. That persistence is the point to hold onto. The scabs that fall off this year’s lambs carry the virus through to next year, in the shed, on the handling gear, on the pasture. A premises does not get orf so much as keep it.
The virus needs broken skin to get in, which is why lesions map onto the places sheep graze and suckle: the lips and gums of lambs, the hoof and horn junction at the coronary band, and, in nursing ewes, the teats, where a lesion frequently opens the door to mastitis. NADIS notes the disease is at its most severe in artificially reared lambs under two months old, which anyone who has run a wet ewe pen through a bad orf year will confirm without needing the reference.
Treatment: mostly, you manage it
The honest position, and NADIS states it plainly, is that treatment is largely unsuccessful, because there is nothing to give against the virus itself. The exception is where scabs pick up a secondary bacterial infection: those cases respond well to a course of injectable antibiotics, typically procaine penicillin or oxytetracycline with a topical spray for three to five days, prescribed and dispensed through your vet. Everything else is nursing: soft feed for sore mouths, an eye on affected lambs’ condition since a lamb that cannot suck slides fast, and stripping or supporting ewes whose teats are hit. Most cases run their course over a few weeks.
Wear gloves. Orf is zoonotic, and NADIS’s advice on protective clothing is not a formality: human orf lesions, usually on the hands, are painful, slow, and a reliable way to lose a week’s work at the busiest time of year.
Vaccination: useful, live, and easy to get wrong
There is a vaccine, and it comes with a rule that sounds backwards until the biology is in view. AHDB’s guidance is that the vaccine must only be used in flocks where orf has been diagnosed by a vet, because it is a live vaccine, Scabigard, the only one on the UK market, and the scabs it produces at the scratch site are themselves infective. Vaccinate a clean flock and you have not protected it; you have introduced the disease you were insuring against.
In a flock that does carry orf, the vaccine earns its place. It goes on by skin scarification, the inner thigh in lambs and behind the front leg in ewes, timed around six weeks ahead of the expected risk period, which in practice means working back from lambing or from whenever the flock’s trouble usually starts. Handle it with the same gloves as the disease. Uptake nationally is thinner than the disease’s ubiquity would suggest: AHDB’s figures have vaccination coverage at 24% of flocks in 2024, having bounced between 16% and 39% over the preceding decade.
Keeping it out of the lambing shed
Because the virus rides on scabs and enters through broken skin, the practical levers are hygiene and abrasion: clean, dry bedding rather than the rough, scabby corners of a shed that has carried the disease before, care with anything that scratches mouths, and quarantine thinking when sheep come onto the holding. None of it makes a farm orf-proof. It moves the odds, which with this disease is what is on offer. The wider pre-tupping and lambing health jobs sit in our sheep breeding guide and lambing season guide, and the flock-level economics of health decisions are in our UK sheep farming guide.
Frequently asked questions
What is orf in sheep?
A highly contagious skin disease caused by a parapox virus, producing scabby lesions on lambs’ lips and gums and on ewes’ teats. The virus survives many months in dried scabs, which is how it persists on a farm from year to year.
How do you treat orf in sheep?
There is nothing that kills the virus. Secondary bacterial infections of the scabs respond to vet-prescribed antibiotics, typically injectable penicillin or oxytetracycline with a topical spray over three to five days. Beyond that it is nursing care while the disease runs its course.
When should you vaccinate for orf?
Only in flocks where a vet has diagnosed orf, about six weeks before the usual risk period. The vaccine is live and applied by skin scratch, and its scabs are infective, so it must never go into a flock with no history of the disease.
Can humans catch orf from sheep?
Yes. It causes painful skin lesions in people, usually on the hands, from handling infected animals or scab material. Gloves and protective clothing are the defence, for the vaccine as well as the disease.
