Labrador weapon in battling kauri killer

Kauri dieback kills the lofty native giants through microscopic spores in the soil that infect the roots and damage tissue. Photo / NZME.

The first dog trained to sniff out kauri dieback disease is showing promise as a weapon against the forest scourge.

Paddy the golden labrador, once rescued from an Auckland home in an emaciated state, has become a star of Auckland Council's biosecurity team after being trained to detect the disease at an early stage.

Thought to have long been in New Zealand but only formally identified in 2008, kauri dieback kills the lofty native giants through microscopic spores in the soil that infect the roots and damage tissue.

Nearly all infected kauri die.

In the past 10 decade, it has wiped out thousands of trees and spread to the Waitakere Ranges, Great Barrier Island, Trounson Kauri Park and Waipoua Forest in Northland, home of our most iconic kauri - Tane Mahuta.

At present, its spread is monitored through an aerial surveillance programme and reports from private landowners.

But now scientists are excited by the difference Paddy could bring to the response effort.

Dr Imogen Bassett, of Auckland Council, said she and her colleagues had been heartened by tests run with Paddy, in which he'd been able to detect dieback disease 86 per cent of the time in the first instance, and then in all cases when given a second chance.

Using a sample of the disease grown on grains of wheat, scientists compared his ability to distinguish between a jar with infected wheat and a jar with uninfected wheat.

Astonishingly, the dog had even been able to tell the disease apart from other Phytophthora in the same genus.

"I'm really confident ... that he can detect specifically that disease," Dr Bassett said.

"So now we're looking at ways ... to see if he can detect the disease within the forest soil environment."

The hope was that Paddy might be used to identify not only the front of a dieback incursion, but also the exact extent of its spread.

"At the moment, when we think we have an infected tree, we need to ship the soil sample off to have it cultured up - but potentially with Paddy, we could get that instant diagnosis."

There was also the possibility of taking the dog through uninfected forests to detect any early signs of disease.

"The other great thing about having a detector dog is he'd have a lot of public appeal - it's an excellent interface for getting the public interested in biosecurity."