Searching for similar movie - please help!

I've been searching for a certain movie for years.

I'm sure I saw it in the 70's as a kid.

I think it was a supporting film, before the main picture.

I wrongly believed it was 'Walkabout', as it mirrored the storyline.

It too featured children lost in the desert/outback, along with their little white dog. (Cairn terrier or West Highland White terrier)

All I do remember though is a scene, where the children mistakenly believe that the native trying to help them, has eaten their dog (which he hasn't).

Is it this movie?

Any ideas?