Concern grows over mystery horse deaths in Victoria as toll rises to 13

Agriculture Victoria is investigating the sudden deaths of a number of horses. The fatalities have caused widespread concern among horse owners and trainers. Photograph: Mick Tsikas/AAP

The death toll of a mystery illness affecting horses in Victoria has risen to 13, with five properties now affected.

Agriculture Victoria began investigating the deaths as a significant event on Sunday after receiving reports that five horses had died on one property within the past two weeks.