Sept. 20, 2021 -- Cobra the dog has been hard at work at the Miami International Airport, sniffing masks proffered by American Airlines employees making their way through a security checkpoint. When she detects an olfactory signal, Cobra will sit down and tell her handler. When this good girl sits, that means Cobra has detected an olfactory signal of the coronavirus, the virus that causes COVID-19.
Cobra is a Belgian Malinois. One Betta is a Dutch shepherd and her partner is Cobra. Their participation in a pilot program is with Florida International University's Global Forensic and Justice Center. The dogs serve as an instant screen for those suffering from COVID-19.
They have a high detection rate, of more than 98%. The program is so popular that they are being extended to the airport for another month.
These dogs and others with the same training can be sent to places where there are many people, like schools, airports, or other areas. COVID-sniffing canines are already in use at some universities.
But building up a big brigade of live animals as disease detectors involves some thorny issues, including where the animals retire once their careers are complete.
"When COVID first arose, we said let's see if we can train these two dogs on either the virus or the odor of COVID-19," says Kenneth Furton, PhD, a professor of chemistry and biochemistry, provost, and executive vice president at Florida International University.
His team had completed a study with what he calls "medical detector dogs," animals that might be able to detect the odor of someone having a seizure. They were able to detect different types of diseases and conditions.
To train a dog how to detect specific smells, it is important to get them to grasp the overall task. Furton states that dogs must first be taught that they are only trained to recognize one particular odor. Dogs can learn to detect any odor once they understand this.
In fact, in addition to detecting seizures, dogs reportedly have been able to identify diabetes and even some cancers, such as ovarian cancer.
Furton said he isn't aware of any past use of dogs for screening infectious disease. It could be that nothing has happened recently to cause COVID to strike with such global fury, causing people to look to their closest friends to help.
Cobra and One Betta got their start learning to identify the presence of laurel wilt, a fungus that attacks avocado trees and kills them, costing Florida growers millions. They can also detect other smells with their experience under their control. It takes only weeks for the dogs to become proficient at this task.
Training the Dogs, Safely
To train Cobra and One Betta on COVID-19 odors, Furton's team first acquired mask samples from people hospitalized with COVID and people who did not have the disease. The virus causes people to produce chemical compounds that they exhale when they breathe. Furton and his coworkers found that masks made by people suffering from COVID had different exhaled compounds than masks from those who did not have it.
After confirming that exhalations could be COVID-specific the researchers trained four dogs, Hubble and One Betta -- who were able to distinguish between masks belonging to people with COVID from a variety of other masks. To ensure that dogs wouldn't get infected, researchers used ultraviolet light to destroy any active virus trace.
The reward for correct selection of a COVID mask by a dog was a chew toy, a red ball. All four dogs were very accurate, but Cobra and One Betta performed better than their trainers. Based on their training scores Cobra was first with 99.45% accuracy. Furton said that One Betta did not perform better than her named, coming in second at 99.45% accuracy. This is still quite good.
Both dogs do well at airport screening. After sniffing the masks at checkpoints, one dog will sit and the other must be checked.
Greg Chin from the Miami-Dade Aviation Department, communication director, said the dogs screened 1 093 persons in 8 days. One case was alarmized. That person had tested positive for COVID 2 weeks earlier and was returning to work after quarantine, and their rapid test after the dog alerted was negative.
Furton says that there are some reports of dogs also alerting before tests can show a positive result, suggesting the dogs’ odor detection can be more precise. The researchers plan to increase their research to determine how narrow the dog-based detection window is.
Chin states that for now the detection dogs have been doing well and the program was extended by 30 days.
Even though this sounds promising, dogs used for screening can pose some ethical and logistical challenges. A large number of dogs need to be retired after training a canine army for deployment at high-volume detection sites. Furton also says the initial training can be lengthy. But, if an electronic device was developed to screen, it could be manufactured quickly.
But the dogs don't necessarily have to go.
Furton said that there is a possibility they might be moved to another form of detection for another disease if needed. He says there's a spiritual connection when you work with dogs. You don't need to use instruments.
Furton says that although the Miami International pilot screening is the primary venue, dogs have done the work at other locations, such as at an emergency center in Florida or in university classrooms.