Control and Prevention of Orf in your Flock
Orf is an听endemic viral听disease within the听UK affecting听sheep and goats.听It can cause significant welfare issues in your flock and have an impact on lamb growth rates. If you听don鈥檛听have it,听keep it out with strict biosecurity.听听
Once infection enters the flock disease control is challenging as it is highly contagious听and can听remain in the environment for听long periods. Isolation of affected animals, disinfection,听vaccination听and the use of waterproof gel barrier should all be considered as part of a control strategy. Consulting with your vet early in an outbreak can help minimise the impact of any outbreak.听听
What is Orf?听
Orf is a听contagious viral听disease caused by a听Paraopox听virus affecting sheep and goats.听Humans can be infected听with farmers and shepherds being at听high听risk听of听contracting it. Infection is spread by direct听contact by听infected animals and through environmental contamination with听infected scabs.听听
The virus can survive in environment for months听and sometimes听years.听Wounds/abrasions to the听skin allow听entry into the body. Scabby lesions听occur usually听around the听mouth and nose of lambs. Infection can then spread to听ewes听teats when lambs are suckling. Consequences of this听include mastitis听and reduced lamb growth rates.听
Infection is usually听self-limiting听lasting听four to six听weeks however infection particularly in young lambs can lead听to reduction听in growth rates听and is a significant welfare concern.听Animals听don鈥檛听develop immunity and can become reinfected. Recovery tends to be quicker in these cases with infection lasting听two to three weeks.听听
What is the risk to humans?听
Infection in humans occurs in the same way with infection entering through wounds. Lesions can be painful and in rare cases can lead to serious infections. Good hygiene is essential and gloves should be worm when handling affected animals听
Diagnosis and听treatment听
If you are concerned you have an听Orf听outbreak,听contact your veterinary surgeon.听To confirm a听diagnosis sample of scabs听can be taken and听submitted听to 伊人直播听veterinary investigation centre. Scabs are tested by PCR for the presence of听Parapox听virus.听
Affected听groups听(where听possible) should听be isolated to reduce spread and particular attention should be paid to hygiene of feeding equipment.听Appropriate disinfectant of the environment with听antivirals should听be performed to reduce risk of reinfection in听subsequent听lambing periods. Antibiotic treatment should only be considered when secondary infections are present e.g.,听mastitis.听听
A licensed live vaccine is available听and can听be used听successfully control听Orf听infections on endemic farms. Vaccine must only be used on farms where听Orf听has been diagnosed by a vet.听Both adult and neonatal animals can be vaccinated听but vaccination听must not be used in ewes in the last听eight听weeks of pregnancy.听听
Seek veterinary advice when using vaccine as听successful disease听control relies on correct application of vaccine. Vaccination in听subsequent听years should be considered for continued disease control.听
A new waterproof gel barrier has recently been trialled in a small number of flocks affected by Orf. Early findings from a recent study suggest it may help create an environment that supports skin healing.听Further larger studies are听required听to further investigate its use however this听initial听study suggests the product may be useful in treating Orf.听
As ever the best advice is听to avoid听infection by strict quarantining of any new animals听purchased听and those returning from shows, winter grazing etc.听
5 top听tips听
- Orf is a zoonotic disease and can spread to humans. Ensure strict hygiene when handling affected animals. Disinfect effectively to reduce spread.听听
- If your flock is free from Orf, keep it that way by quarantining all incoming and returning animals.
- Seek advice from your听farm vet听if you are concerned you have Orf in your flock.听听
- The Orf听vaccine should only be used under veterinary guidance.听
- Consider the use of new waterproof gel barrier to aid healing in infected animals.
Lynn Gibson,听伊人直播听Veterinary Investigation Officer, Lynn.Gibson@sruc.ac.uk
Posted by SAC Consulting on 17/04/2026
