When Ali, one of Paul Diamond's "best workers" was badly injured in a traumatic farm accident six months ago, the idea of giving up on the working dog was too hard to bear.

But this week, the story of Ali's journey from spinal injury and paralysis to mustering sheep again has become an international sensation after a video of the wheelchair-bound kelpie amassed more than one million views on social media.

"About six months ago she had a traumatic spinal injury where she got backed up against a race by a sheep, and from there it went downhill and she lost the use of her back legs," Victorian farmer Paul Diamond said.

Mr Diamond is first to admit that five-year-old Ali has always been a favourite, and to have her back on the farm this week rounding up sheep has filled him with pride.

"I can't believe it. It's working," he said.

"I was blown away that she could zoom through this paddock and actually get around the sheep and not just do it for the bits and giggles, but actually be quite handy."