Which of the following diseases affects sheep or cattle?

Scabies is a disease that primarily affects livestock, including sheep and cattle. It is caused by the Sarcoptes scabiei mite, which leads to intense itching, hair loss, and skin lesions. In these animals, scabies can result in severe discomfort and can compromise their overall health and productivity. The disease is highly contagious within species, making it a significant concern for flock or herd management.

Other diseases listed do not typically affect sheep or cattle. Avian tuberculosis is associated with birds, such as poultry. Equine viral arteritis primarily affects horses and not livestock like sheep or cattle. Infectious encephalomyelitis, particularly Eastern and Western forms, affects horses and is not a concern for ruminants. Consequently, scabies is the clear choice when identifying a disease that directly impacts sheep and cattle.