The story of Andy Cunningham and his dog Meg was already remarkable - the Dunedin man credits the labrador-huntaway cross with helping him walk again after a back injury left him paralysed.

However, the story moved into the realm of the unbelievable yesterday when Cunningham and Meg were reunited, five weeks after his beloved dog disappeared following a car crash.

Andy Cinningham and Meg. (Photo / Stephen Jaquiery)

Meg, 6, has a dislocated or broken right leg, a dislocated or broken toe in her left leg, and is badly dehydrated but has somehow survived weeks in the outdoors.

"She taught me how to walk again; now I'll have to teach her how to walk again,'' Cunningham said.

"It's just incredible - we never believed we would see her again.''

Meg was found at lunchtime yesterday by farmer Raewyn Waller in a remote gully of her Purakaunui property, about 800m from where the car in which Meg was travelling crashed and rolled January 31.

The Cunninghams were on holiday at the time and a friend was taking Meg to the beach for a walk when the crash happened.

Volunteers turned out in force to look for Meg, but after five weeks her owners feared the worst.

"It just goes to show you should never give up hope,'' Cunningham said.

"We were sitting down to lunch when we got a call from Raewyn saying 'we think we've got your dog in the field below our farm'.''

The Cunninghams dashed to the Waller farm and then took a four-wheel-drive to the rugged spot where Meg had been seen.

"We got to a gully and I looked and 50m away was my dog,'' Cunningham said.

"I called her and she got up and wagged her tail.''

After a difficult recovery, Meg was taken to the Wildlife Hospital, which Cunningham is co-chairman of, for a check-up.

She was badly injured, severely dehydrated and painfully thin.

A Christchurch specialist is assessing scans of Meg's legs to determine if they can be saved.

"She's very perky and we're feeling pretty optimistic,'' Cunningham said.

"We have no idea what she's been through, but it must have been fairly horrible. But she's back, and we've just been crying our eyes out.''

The person who first saw Meg is eligible for a $2000 reward posted by Cunningham.

They had declined the reward, and if they turned it down again the money would be donated to the Wildlife Hospital, Cunningham said.

However, that won't be the only charity which will benefit from Meg being
found.

"Alison [Cunningham's wife] said she was going to get her head shaved for leukemia, Shave For A Cure, if Meg came back,'' Cunningham said.