Horse trainers have been reminded of the risks of the Hendra virus and methods in place to minimise the risk of infection in the wake of recent cases in Queensland and northern NSW.

Racing NSW chief veterinarian, Dr Craig Suann has posted a comprehensive list of protocols surrounding the virus which has struck three horses in the Macksville area of NSW in recent weeks.

The latest unvaccinated horse died on Sunday.

Suann has detailed the symptoms and biosecurity measures to help prevent the spread of the bat-borne virus which is also fatal to humans.

The full measures are on www.racingnsw.com.au.