Dogs Demonstrate Ability to Detect COVID-19

Monday, May 18, 2020

It is no secret that dogs have long been used for purposes other than companionship. Because of an acute sense of smell, dogs can be trained in medical arenas to detect cancer, diabetes, and other chronic diseases or conditions. You may have also seen the incredible sniffing power of dogs used in missing persons cases, illegal drugs, and hunting applications. Therefore, researchers are now expanding upon this innate ability to train them to detect COVID-19.

The overall hope is for dogs to be able to detect COVID-19 in patients that are not yet displaying any symptoms. The thought process is basically to use this tool as a large-scale screening process for highly populated areas such as airports, sporting events, and recreation areas. [1]

Dr Claire Guest, CEO and Co-Founder of Medical Detection Dogs, says: “In principle, we’re sure that dogs could detect COVID-19. We are now looking into how we can safely catch the odor of the virus from patients and present it to the dogs.

“The aim is that dogs will be able to screen anyone, including those who are asymptomatic and tell us whether they need to be tested. This would be fast, effective and non-invasive and make sure the limited NHS testing resources are only used where they are really needed.”

Training dogs to detect Coronavirus.

Dogs are trained to detect COVID-19 by using a biologic sample from a COVID-19 patient as a training aid, but containment of the sample can be challenging and dog and handler safety is a top priority. SciK9 has developed the TADD (Training Aid Delivery Device), which uses a Sterlitech oleophobic membrane to keep the hazardous material contained, while allowing odor to permeate. Oleophobic membranes work by repelling liquids, including low-surface-tension biologic samples, without blocking airflow.

Contact SciK9 https://www.scik9.com/ for more information on the TADD.

Understanding the Canine Olfactory Sense

Dogs have up to 300 million scent receptors versus the 6 million scent receptors that humans have. Additionally, the portion of the dog’s brain responsible for analyzing various smells, is significantly larger than that of humans. A dog sense of smell is said to be 40x greater than ours and can detect some odors in parts per trillion. [5,8]

Alexandra Horowitz, author of Inside a Dog and dog-cognition researcher at Barnard College makes an interesting comparison: She suggests that humans may take notice at the addition of on teaspoon of sugar added to our coffee. In startling comparison, she states a dog could detect a teaspoon of sugar in a million gallons of water (the size of 2 Olympic-sized pools). [1,8]

How Do Dogs Smell?

Brent Craven, a bioengineer at Pennsylvania State University, pioneered a methodology to help better understand the dog’s olfactory system. He modeled airflow and odor transport using high-resolution MRI scans of a lab cadaver's nose. His research team discovered some unique findings about how dogs smell. The team made two important discoveries:

Dogs have two distinct pathways of flow for respiration and olfaction.
Dogs have a recessed area in the back of the nose dedicated to olfaction.

In fact, they note approximately 12 percent of the inspired air collects to this recessed region filtering its way a sophisticated bone structure system known as turbinates. The function of the turbinates is to sieve odor molecules based on various chemical properties.

This is accomplished via the tissues that lines the turbinates referred to as olfactory receptors. These receptors can distinguish the different odor molecules by their shape and dispatch electrical signals to the brain for analysis. [8]

Let's suppose they're just 10,000 times better," says James Walker, former director of the Sensory Research Institute at Florida State University.

"If you make the analogy to vision, what you and I can see at a third of a mile, a dog could see more than 3,000 miles away and still see as well.

What Factors That Can Influence a Dogs Olfactory System?

Genetics: Certain breeds are known to have elements that make them more adept at sniffing out scents and odors. A good example is the bloodhound. They have ears that drag the ground and bring up certain scents.

Health: The overall health of a dog matters. Implications such as heart disease, degenerative disease, or organ failure can affect the olfactory function.

Management: Dogs can be trained for specific duties and specific scents. In the scope of this training, the olfactory system can be developed and nurtured to perform at a higher level of consistency and accuracy.

Microbiota: Studies show the microbiome is very sensitive in dogs. They revealed in a study that even meals containing high fat contents and given at inconsistent times affected the olfactory system in both dogs and mice. Diet, exercise, and digestion all seem to play a big role in a dog’s olfactory function.[7]

COVID-19: Canine Detection Programs and Research

https://unsplash.com/photos/2jvxtiGqr8Y Photo by Jason Jarrach on Unsplash

Dog training programs are actively underway at the Working Dog Center as part of the University of Pennsylvania School of Veterinary Medicine. Another similar program was also conducted at the LSHTM (London School of Hygiene and Tropical Medicine). They published a paper following a study conducted at LSHTM.

The study results indicated the dogs can sniff up to 750 people at a time. The training involves the dogs being given coronavirus patients' face masks to sniff to discover if COVID-19 has an identifiable odor. [9]

Professor James Logan, the head of the department of disease control at LSHTM, said: "It's early days for COVID-19 odor detection. We do not know if COVID-19 has a specific odor yet, but we know that other respiratory diseases change our body odor so there is a chance that it does.

"It's early days for COVID-19 odor detection. We do not know if COVID-19 has a specific odor yet, but we know that other respiratory diseases change our body odor so there is a chance that it does. And if it does dogs will be able to detect it. This new diagnostic tool could revolutionize our response to COVID-19."

References: