Contagious ecthyma is a highly contagious, zoonotic, viral skin disease that affects sheep, goats and some other domesticated and wild animals. The skin lesions are painful and often occur on the mouth and muzzle, where they can cause anorexia or starvation. Lesions on the udder may result in the abandonment of offspring, and foot lesions can cause transient lameness. Secondary bacterial infections can occur and, in rare cases, the lesions may extend into the internal organs. Although contagious ecthyma usually resolves spontaneously and the mortality rate is generally low, deaths can occur from sequelae such as secondary infections or failure to nurse. The economic impact can be significant. Severe generalized infections have also been described occasionally.

Most infections in humans are localized and heal spontaneously; however, large, poorly healing lesions can occur in people who are immunosuppressed.