08/17/2011 09:34 EDT | Updated 10/17/2011 05:12 EDT

Dogs can be trained to sniff out lung cancer, says study

TORONTO - Man's best friend may become even more indispensable after a study found dogs may be used to detect lung cancer with a high accuracy.

News reports say researchers in Germany found that trained dogs could detect a tumour in 70 per cent of patients.

However, the scientists writing about their small study in the European Respiratory Journal, say they do not know which chemical the dogs are detecting.

Researchers first found out in 1989 that dogs could detect cancer and other studies through the years have suggested canines could detect skin, bladder, bowel and breast cancers.

It is thought that tumours produce "volatile chemicals" which a dog can detect.

German researchers trained three shepherds and a lab to detect lung cancer by taking a whiff of a fleece filled tube.