“Sore mouth,” also known as “scabby mouth,” or contagious ecthyma, is a viral infection caused by a member of the poxvirus group (specifically orf virus) and is an infection primarily of sheep and goats. The scabs of infected animals contain virus, can fall off, remain in the environment and serve as a source of infection to susceptible animals. A flock can become infected through contaminated bedding, feed or trucks, or by direct contact with infected animals (e.g. replacements brought onto the operation or at shows).

Animals may become infected with sore mouth more than once in their lifetime although infections are likely to occur years apart. Young animals will have the most visible disease because they have not likely been exposed to the virus before and because their immune systems are still developing.

People can become infected with the virus that causes sore mouth. A person who comes into contact with virus from an infected animal or equipment (such as a harness that has rubbed the animal’s sores) can potentially get infected. People often develop sores on their hands (see photos). The sore may be painful and can last for 2 months. People do not infect other people. Sores usually heal without scarring.