Definition of backing dog in English:

backing dog

noun

Australian, NZ
  • A sheepdog trained to run over the backs of sheep while driving them in confined spaces.

    ‘a backing dog is worth a lot to the station which owns him’
    • ‘As a backing dog you'd have thought he had wings.’
    • ‘A backing dog needs special training and is much in demand.’
    • ‘A dog trained to do this is called a backing dog, and he's worth a lot to the station which owns him.’
    • ‘Experienced field trial dogs will frequently see this scenario and move toward the action in hopes of getting involved, usually as a backing dog.’
    • ‘This agility came from his mother who was trained as a backing dog.’