For thousands of years, dogs (domesticated descendants of wolves) have been considered to be man’s best friend. One of the ways that friendship has been manifested is the use of the dog’s highly-developed sense of smell to detect signs of disease in humans.
Since this is usually possible long before any more obvious symptoms may be evident to the diseased person, it may enable life-saving medical intervention for the individual concerned. Now, there’s also evidence that a similar disease-detection role could be played by dogs in the service of plants (or, rather, for the humans who own the plants and who would/should use that information to treat the damaged botanics).
The proof-of-principle for this comes from work by Julian Mendel et al.. In this instance three dogs – one Belgian Malinois and two Dutch Shepherds – were trained to ‘sniff-out’ the presence of laurel wilt disease (caused by Raffaelea lauricola) in commercially-important avocado (Persea americana) trees. It worked, and importantly, enabled infection to be detected before visible symptoms would have alerted the human guardian of the trees to any problem.
Identifying so-called presymptomatic trees should give time for interventions to be put in place to deal with the infection; when symptoms are obvious to humans it is usually at a stage where the disease is very difficult to control. The canine trio involved not only demonstrated the ability to locate laurel wilt–diseased avocado wood with high accuracy and speed, but were also capable of high levels of performance even in harsh weather conditions such as high heat and humidity.
Is this a case of a dogs barking up the right tree? Whatever, we predict more examples of this doggedly determined disease detection work in future.