Sheep Orf Contagious Ecthyma: Welfare and Zoonotic Risk

Orf is a highly contagious viral skin disease of sheep and goats causing painful proliferative lesions around the mouth and face, with significant welfare impacts particularly on nursing lambs.

Key Facts

Orf is caused by Parapoxvirus ovis and causes proliferative pustular lesions primarily around the mouth and nose
Young lambs are most severely affected with lip lesions causing difficulty nursing and risk of starvation
Ewes can develop orf lesions on teats from nursing infected lambs causing painful mastitis and rejection of lambs
The virus is highly stable in the environment and can persist on premises for months to years
Vaccination using live virus from lesion material provides protection but does not eliminate the virus
Orf is a zoonotic disease that can cause painful self-limiting lesions in humans who handle infected animals
The economic impact includes lamb deaths, reduced growth rates, and mastitis in affected ewes

Welfare Considerations

Orf causes significant welfare harm through painful mouth lesions that prevent normal feeding, with lambs at greatest risk of starvation and secondary infection. Teat lesions in ewes cause pain during nursing and may lead to mastitis and rejection of lambs. The highly painful nature of proliferative skin lesions is well-established and untreated severe cases cause chronic discomfort. Farm hygiene and vaccination are the primary prevention tools but neither eliminates the disease completely. Supporting affected animals through soft feed provision and pain management where indicated reduces welfare compromise during outbreaks.

What You Can Do

Vaccinate ewes and lambs against orf before the primary risk period following veterinary advice
Provide supplementary feeding to lambs with mouth lesions that cannot nurse effectively
Isolate affected animals to reduce spread and monitor closely for secondary infection
Wear gloves when handling animals with suspected orf to protect against zoonotic transmission
Implement pen hygiene measures to reduce environmental virus load
Seek veterinary advice for severe cases and consider pain management for badly affected animals
Report unusual skin disease presentations to your vet for accurate diagnosis before assuming orf