epizootic
noun
epi·zo·ot·ic ˌe-pə-zə-ˈwä-tik 
-zō-ˈä-
: an outbreak of disease affecting many animals of one kind at the same time
also : the disease itself
epizootic adjective
Example Sentences
Recent Examples on the Web With Covid keeping us at home, many ecologists are unaware of potentially the most important non-human epizootic occurring since white-nose. 
Sophie Lewis, CBS News, 19 May 2020 African swine fever decimated the country’s pig population in 2019 in what lovers of Greek etymology would have insisted was an epizootic—relating to animals—and not an epidemic—relating to people. Jacky Wong, WSJ, 10 Mar. 2020 Unfortunately an epizootic of African swine fever has recently wiped out at least a third of all the pigs in China. The Economist, 10 Oct. 2019
Sophie Lewis, CBS News, 19 May 2020 African swine fever decimated the country’s pig population in 2019 in what lovers of Greek etymology would have insisted was an epizootic—relating to animals—and not an epidemic—relating to people. Jacky Wong, WSJ, 10 Mar. 2020 Unfortunately an epizootic of African swine fever has recently wiped out at least a third of all the pigs in China. The Economist, 10 Oct. 2019 Word History
Etymology
borrowed from French épizootique "pertaining to a disease affecting many animals at once," coinage modeled on épidemique epidemic entry 1, from Greek epi- epi- + zôion "animal" + French -otique -otic entry 1 — more at zoo-
Note: The Oxford English Dictionary and Trésor de la Langue Française both treat épizootique as a derivative of épizootie, but the noun is attested later and is more likely a back-formation from the adjective, on the model of épidémique : épidémie.
First Known Use
1748, in the meaning defined above
Medical Definition
epizootic
noun
epi·zo·ot·ic ˌep-ə-zə-ˈwät-ik
: an outbreak of disease affecting many animals of one kind at the same time
also : the disease itself