An outbreak of disease affecting many animals of one kind at the same time. The farm was quarantined due to an epizooty that spread rapidly among the cattle.
A disease that is temporarily prevalent and widespread among a population of animals (an animal epidemic). Ranchers feared that an epizooty could wipe out their herds.
The occurrence or period during which such a disease spreads widely among animals. The 1872 epizooty crippled transportation across the eastern United States.