Enzootic describes the situation where a

disease A disease is a particular abnormal condition that adversely affects the structure or function (biology), function of all or part of an organism and is not immediately due to any external injury. Diseases are often known to be medical condi ...

pathogen In biology, a pathogen (, "suffering", "passion" and , "producer of"), in the oldest and broadest sense, is any organism or agent that can produce disease. A pathogen may also be referred to as an infectious agent, or simply a Germ theory of d ...

is continuously present in at least one species of non-human animal in a particular region. It is the non-human equivalent of

endemic Endemism is the state of a species being found only in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also foun ...

. In

epizoology Epizootiology, epizoology, or veterinary epidemiology is the study of disease patterns within animal populations. See also * Epizootic * Epidemiology Epidemiology is the study and analysis of the distribution (who, when, and where), patterns ...

, an infection is said to be "''enzootic''" in a population when the infection is maintained in the population without the need for external inputs (''cf''.