A number of researchers from various universities have joined together to try and develop a mechanical device that can rival the scenting ability of dogs to detect diseases in people. No one denies that dogs have a remarkable ability to detect the early stages of disease in humans. But the cost of training the dog and the dog’s length of service makes using them expensive. If scientists can develop a device that can equal a dog’s nose it would reduce a lot of the cost.
What has proven elusive to scientists is that dogs can pick up connections that researchers cannot mimic in a machine. For example, some dogs that have been trained to detect one type of cancer will identify other types of cancer as well. When the researchers tried to determine what the dogs were detecting, they were not able to. The differences were not detectable by current tests. What complicates the problem is that the different cancers that were detected by the dogs do not have any biomolecular signatures in common. The dogs were able to generalize from one kind of cancer to be able to identify others.

The detection system that has been developed is 200 times more sensitive than a dog’s nose but the machine cannot figure out the elusive patterns that the dog can, that allows the dog to detect various cancers. In other words, the machine cannot think and make the connections. Until the researches solve the mystery, the machine cannot replace the dog.
The important point for people who use dogs for scent detection work is that dogs are capable of analyzing scent in a much more complex way then they have been trained to do. The bottom line is that if your scent dog gives you an indication that does not make sense to you, trust your dog and look further.