What is "epizootic"

epizootic \ep`i*zo*["o]t"ic\, n. [PJC] Epizootic \Ep`i*zo*["o]t"ic\, Epizooty \Ep`i*zo"["o]*ty\, n. [F. ['e]pizo["o]tie.]

1. A disease attacking many animals at the same time; an epizootic disease.

2. A murrain; an epidemic influenza among horses.

animal equivalent of epidemic, 1748, from French épizootique, from épizootie, irregularly formed from Greek epi "on, upon" (see epi-) + zoon "animal" (see zoo-). As an adjective from 1790.

a. 1 (context epidemiology English) Like or having to do with an ''epizootic'': epidemic among animals. 2 (context geology rare English) contain fossils. n. 1 (context epidemiology English) An occurrence of a disease or disorder in a population of non-human animals at a frequency higher than that expected in a given time period. Compare '''''epidemic'''''. 2 A particular epizootic (epizootically-occurring) disease. 3 (context dialectal humorous often in the plural English) A disease or ailment.

a. (alternative spelling of epizootic English) n. (alternative spelling of epizootic English)

adj. (of animals) epidemic among animals of a single kind within a particular region; "an epizootic disease"

In epizoology, an epizootic (from Greek: epi- upon + zoon animal) is a disease event in a nonhuman animal population, analogous to an epidemic in humans. An epizootic may be: restricted to a specific locale (an " outbreak"), general (an "epizootic") or widespread (" panzootic"). High population density is a major contributing factor to epizootics. Aquaculture is an industry sometimes plagued by disease because of the large number of fish confined to a small area.

Defining an epizootic can be subjective; it is based upon the number of new cases in a given animal population, during a given period, and must be judged to be a rate that substantially exceeds what is expected based on recent experience (i.e. a sharp elevation in the incidence rate). Because it is based on what is "expected" or thought normal, a few cases of a very rare disease (like a TSE outbreak in a cervid population) might be classified as an "epizootic", while many cases of a common disease (like lymphocystis in esocids) would not.

Common diseases that occur at a constant but relatively high rate in the population are said to be " enzootic" (cf. the epidemiological meaning of " endemic" for human diseases). An example of an enzootic disease would be the influenza virus in some bird populations or, at a lower incidence, the Type IVb strain of VHS in certain Atlantic fish populations.

An example of an epizootic would be the 1990 outbreak of Newcastle disease virus in double-crested cormorant colonies on the Great Lakes that resulted in the death of some 10,000 birds.