Specially trained “glycaemia alert dogs” were able to detect when their owners’ blood sugar levels were outside their normal range and warn them of the fact, researchers found.
It is believed that the dogs are able to detect potential danger because their keen sense of smell can detect chemical changes in their owner’s sweat or breath.
Similar studies have suggested that dogs may be able to detect cancer by catching the scent of chemical compounds released by tumours.
In the new project, funded by pet training specialists The Company of Animals, studied seventeen dogs which had been trained to spot when their owner’s blood sugar levels began to drop too low or rise too high.
Some of the dogs had been donated and trained by the Medical Detection Dogs charity, while others belonged to participants and were specially trained for the study.
Results published in the PLOS ONE journal showed that all seventeen patients reported benefits, including fewer ambulance call-outs and fainting episodes, and greater independence.
Data recorded by the patients suggested that the dogs had been able to warn their owners of high or low blood sugar with an accuracy significantly above the level of chance, although the success rate varied from animal to animal.
Dr Nicola Rooney, who led the study, said current electronic systems designed to do the same job have “numerous limitations” and that dogs could offer “significant improvements”.
She added: “Some of the owners also describe their dogs respond[ing] even before their blood sugars are low but as they start to drop, so it is possible that the dogs are even more effective than this study suggests.
“While it is believed that dogs use their acute sense of smell to detect changes in the chemical composition of their owner’s sweat or breath to respond to glycaemic control, further research is now needed to further understand how dogs carry out this amazing task.”