Dogs Can Sniff Out Disease Responsible for Over 300 Million Tree Deaths in the US

Avocado trees in Florida are about to be safer from a disease that has caused the death of more than 300 million laurel trees in the US alone. Laurel wilt is a vascular disease caused by the fungus Raffaelea lauricola that affects and kills members of the laurel tree family.

Devastating effects

The lethal pathogen in not only untreatable but it also spreads quickly and without notice to other surrounding trees via root grafting making it difficult to contain and deter. In South Florida, laurel wilt threatens the region’s most economically important fruit crop: the avocado.

According to the University of Florida, the region has lost over 9,000 trees due to laurel wilt since 2011. While much research had been done, no viable solutions had yet to be found until now.

A study out of Florida International University has found that dogs can sniff out laurel wilt-affected wood from avocado trees before the disease has time to show infection and therefore spread. The paper, published in Hort Technology, is the work of Julian Mendel, Kenneth G. Furton, and DeEtta Mills.

The article reveals that three types of dogs were tested, "one Belgian Malinois and two Dutch Shepherds."  The researchers undertook 229 experiments that saw only 12 cases of false alerts.

The dogs identified the pathogen accurately even in extreme conditions such as high heat and humidity. The authors conclude that “canines can detect laurel wilt–affected wood and the laurel wilt pathogen and may be useful in the detection of laurel wilt–diseased trees in commercial groves.”

Man's best friend at work

For those worrying about the potential violation of animal rights in serving as diseases detectors, the authors say the dogs responded well to training and were happy to help. "The old saying that 'dogs are man's best friend' reaches far beyond a personal bond with their handler and trainer," said Mills in a statement.

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"It is depicted in their excitement every day as they deploy to the groves. Man's best friend may even help save an industry," added Mills.

Mills also said that the cuddly canines are the "best 'technology' so far that can detect a diseased tree before external symptoms are visible." Since no treatment is currently available for laurel wilt disease, the next best alternative is early detection and elimination to contain further spread.

This is not the first time that dogs have been used for agricultural purposes. Previous studies have seen man's furry companions assist with the detection of other invasive species such as spotted knapweed and in the identification of citrus disease.

The paper is entitled "An Evaluation of Scent-discriminating Canines for Rapid Response to Agricultural Diseases." Hort Technology is a publication by the American Society for Horticulture Science (ASHS), founded in 1903 to advance horticulture research.