As of March 30 there were 18 properties with confirmed cases of pigs with the virus across the Wangaratta, Moira, Greater Shepparton, Campaspe, Gannawarra, Loddon, Greater Bendigo and Northern Grampians local government areas.
More suspected cases are being investigated.
An Agriculture Victoria spokesperson said a horse from northern Victoria had displayed mild signs of disease but had recovered well.
The horse had no history of travel interstate or overseas.
"Due to the nature of the disease in horses it’s not possible to fully confirm whether the horse was exposed to JEV or a closely related virus already known to exist in Australia,“ the spokesperson said.
“Testing is inherently more complex in horses than in pigs. Agriculture Victoria’s incident management team is conducting surveillance activities and providing advice and information to farmers, livestock and horse owners.”
Testing for the virus in horses can be difficult to interpret as available tests pick up a group of closely related viruses rather than being for one specific virus.
Even advanced testing may not always identify the most likely virus causing the positive result in horses.
Only infected mosquitoes can spread the virus.
Horses cannot transmit the disease back to mosquitoes, which means horses cannot transmit the disease to other horses or humans.
Agriculture Victoria is continuing to work with groups, including veterinarians working in the pig and horse industries, to increase awareness of the disease and its effects.
For more information about JEV visit the Agriculture Victoria website.
