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(veterinary medicine)
Affecting many animals of one kind in one region simultaneously; widely diffuse and rapidly spreading.
An extensive outbreak of an epizootic disease.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.



a widely spreading contagious disease (infectious or infestatant) of animals, with morbidity far in excess of that ordinarily (sporadically) observed in a particular locality. The study of epizootics is called epizootiology.

An epizootic is characterized by the steady spread of an infectious disease and a microbe-carrier state among animals. An epizootic can occur only in the presence of a number of interdependent elements that constitute an epizootic chain: the source of the causative agent (a diseased animal or animal microbe-carrier), live transmitters or environmental factors conducive to infection, and susceptible animals. The outbreak and spread of an epizootic are influenced by geographic, climatic, soil, and other environmental conditions and economic factors, including agricultural conditions, as well as social upheavals, such as war or economic crisis. The nature and duration of an epizootic vary depending on the means of transmission of the causative agent, the length of the incubation period, the ratio of diseased to susceptible animals, the conditions under which animals are maintained, and the effectiveness of the countermeasures.

Epizootics of certain diseases may occur periodically, usually every few years. They tend to break out seasonally and to have specific stages of development. All of these characteristics are most evident when the epizootic progresses spontaneously. Intervention by man, specifically the use of countermeasures, as in the USSR, to a considerable degree prevents the spread of epizootics.

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.
References in periodicals archive ?
Epizootic haemorrhagic disease virus in Reunion Island: evidence for the circulation of a new serotype and associated risk factors.
There were no outbreaks of acute infectious diseases registered in Kyrgyzstan, the epizootic situation, including foot and mouth disease, is prosperous", the State Inspectorate assured.
Secondly, because some termite cadavers were showing signs of bacterial growth, we hypothesized that the colony may have succumbed to a bacterial epizootic. We isolated 4 strains of bacteria (Gram-rods, Gram + Coccobacillus, Gram + rods, Gram + Bacillus, identification according to Holt et al.
An epizootic is the classic manifestation of plague where there is a progressive but rapid demise of large numbers of susceptible hosts and bystander species in large areas.
Of the 983 serum samples, 798 were collected from epizootics involving low and high pathogenic H7N1 viruses, and 185 were collected from epizootics caused by a low pathogenic H7N3 virus.
KEY WORDS: Homarus americanus, lobster, epizootic shell disease, bacterial infection, chitinolytic bacteria, 16S rDNA
Although virus activity was detected for the first time in many southern states in 2001, the simultaneous appearance of two epizootic foci very early in 2001--one in the mid-Atlantic region and one in the southeast along the common borders of Florida, Georgia, and Alabama-suggests that WNV was introduced into the southern states by migrating birds in late 2000, but circulated at levels below the detection threshold of surveillance.
Having survived the foot-and-mouth epizootic with our 260 hill sheep we have experienced the tragedies arising from the computer modelling for the "control" of foot-and-mouth disease which was based on false or inaccurate assumptions.
An epizootic of Florida manatees associated with a dinoflagellate bloom.
"Health care providers in areas with documented epizootic activity should consider West Nile virus infection in persons with suspected viral meningitis (especially among adults) or encephalitis (regardless of age)," the report stated.