Dogs learning to sniff out diseases from urine samples

Researchers are teaching a select few Waikato dogs to sniff out a tropical disease known as snail fever.

Schistosomiasis, known as snail fever, is caused by a parasitic worm and can cause serious complications.

Waikato University's Scent Detection Research group is training dogs to identify infected urine samples.

Director of the unit, Associate Professor Tim Edward told Checkpoint the goal was to find out whether dogs could tell the difference between people who had snail fever and those who did not.

There had not been any research on whether it was possible to identify people who had the disease by using scent, he said.

"This is really a pilot project to see if they can do it, if they can, it suggests this might be a way of screening people to see if they might have the disease in places where it's likely to affect people, typically in developing countries."

Edward said initially they had to train the dogs using an automated apparatus.

"[It] allows them to indicate a sample is positive by holding their nose in the port where they could access the sample, or sniffing a sample and pressing a lever on the side of the apparatus.

After that the dogs were introduced to the odour that researchers wanted them to learn which in this case was urine samples from people infected by the disease, he said.

The dogs were also introduced to urine samples of people who were not infected, he said.

"So they can start to learn to reject those negative ones and indicate on those positive ones."

He described the apparatus as a rotating carousel and the dogs could access one sample at a time from the panel on the front of it.

"If they're correct and they've indicated on a positive sample then it automatically gives them a food reward."

Asked whether they used particular breeds of dogs in the research, he said all dogs had incredibly sensitive olfaction or sense of smell, he said.

"They're pet dogs from the community but we screen them to see which dogs really perform well in the laboratory environment and seem to enjoy being here," he said.

"Our top performer at the moment is chocolate labrador named Mac and it's actually quite exciting because even though we're only about six to eight weeks into the project, he's already showing an ability to discriminate between positive and negative samples."

That was with samples that Mac had never sniffed before, so the first time he came across a sample for the first time he was starting to "quite accurately tell us whether they're positive or negative".

Edward said snail fever was a nasty disease which sounded a bit like something out of a horror or science fiction film plot.

"This flat worm spends part of its life cycle in a freshwater snail and then it leaves the snail and lives in a microscopic form in fresh water and if people are in the water, come into contact with the water it can actually penetrate their skin and then it lives inside their circulatory system and breathes and lays eggs and then those eggs get lodged in their tissues, that can be their bladder or their liver other parts their intestines.

"It creates chronic inflammation and can stop the growth of children and it can even lead to certain types of cancer, so it's really actually quite serious. It affects over 200 million people globally."