The largest study ever done on cancer-sniffing dogs has found they can detect prostate cancer by smelling urine samples.
Dogs may offer a more accurate, and far less uncomfortable way, of being tested for prostate cancer, according to new research.
Dr Gian Luigi Taverna from the Humanitas Research Hospital in Milan, Italy, presented his team's findings over the weekend at the American Urological Association.

Their study involved the urine samples of 677 people - 320 of which were prostate cancer patients at different stages of the disease, Roshni Mahesh reports in the International Busines Times.
They had two sniffer dogs examine the samples and trained them to sit down if they detected cancer - what the dogs look for is chemicals emitted by a tumour, known as volatile organic compounds, or VOCs.
After repeated tests, one dog detected cancer with 98.9% accuracy and the other with 97.3% accuracy. The rest of the time, they identified false positives.

Although more research needs to be done, these dogs are already doing a better job than our current tests - prostate cancer has no symptoms in the early stages so can often go undiagnosed before it's too late.
The researchers hope their work will help improve technology and lead to new diagnostic methods for this type of cancer.
Scientists at the University of Pennsylvania are also working on a similar project, and have trained dogs to detect ovarian cancer with 90% accuracy.