epizootic
Concise Oxford English Dictionary © 2008 Oxford University Press:
epizootic /ˌɛpɪzəʊˈɒtɪk/
▶adjective (of a disease) temporarily prevalent and widespread in an animal population.
– origin C18: from Fr. épizootique, from épizootie, from Gk epi ‘upon’ + zōion ‘animal’.
'epizootic' also found in these Oxford entries:

