University of Adelaide researchers are investigating the potential causes of a mystery illness which suddenly struck down 14 horses across South Australia last year, eight of them fatally.

The horses became suddenly ill over the winter months of 2014 with acute signs of sweating, rapid breathing, muscle trembling, weakness, and sometimes loss of coordination. Some horses died very rapidly while others fully recovered. The 14 known cases were in 10 different locations across South Australia.

The researchers are searching for common factors between the cases and aim to establish a protocol which can be used to examine future cases.

One suspect is the weed marshmallow, Malva parviflora, or small-flowered mallow