ep·i·zo·ot·ic 
(ĕp′ĭ-zō-ŏtĭk)
(ĕp′ĭ-zō-ŏtĭk)adj.
Occurring at the same time among an unusually large number of animals in a particular geographic area. Used of a disease.
n.
An epizootic disease.
[EPI- + ZO(O)- + -OTIC.]
ep′i·zo·oti·cal·ly adv.