When you walk into the lobby of Doctors Hospital of Sarasota, you'll likely be greeted by a wagging tail and tip-tapping puppy paws.

Meet Buffy, the two-year-old service dog trained to sniff out Covid-19. Buffy, who was trained in a scent detection pilot program at Southeastern Guide Dogs, screens about 20 to 40 people entering the hospital per day. She is able to determine, within seconds, if someone is positive with the virus based on the scent of their shoes.

Doctors Hospital is the only hospital in the United States using a service dog in this way.

Since April 2021, Buffy has helped bring efficiency and an extra layer of protection to the testing process at the hospital. Regular swab testing and temperature checks still occur, but with the current resurgence in positive cases and hospitalizations in Florida and in Sarasota-Manatee, Doctors Hospital CEO Bob Meade says Buffy has been a great help. She detects Covid-19 with 95 percent accuracy.

"If she smells your feet and lays down next to you, you have Covid," says Buffy's handler Grace Welsby. "If she walks past you, you are negative."

Welsby gives Buffy a treat to reinforce her each time. She works with Buffy three times a week.

"Within Buffy's first week of working here, she detected Covid in a patient who didn't know they had it and was brought to the emergency room. We tested the patient and Buffy was right," says Welsby. "Her sense of smell is impressive."

Disease detection is an area of service dog training that many dogs undergo. Some dogs can alert owners of elevated levels of the stress hormone cortisol, which is particularly helpful in patients with anxiety or PTSD. Some can even alert diabetic patients of blood sugar spikes and crashes.

All training for this process begins the same way.

"A sample of the scent—in this case, a saliva sample from a Covid-19 positive patient at the hospital—is kept in a canister and placed on an apparatus shaped like a wagon wheel," says Meade. "Many other competing scents are also placed in canisters, like cinnamon and mint. The dogs are trained to sniff out the 'target scent,' lay near it, and are given a treat to reinforce the behavior."

After months of this training and continual practice, Buffy is able to differentiate the scent of Covid-19 from that of an ordinary smell. To keep this fresh in the dog's mind, Welsby keeps a metal tin with a deactivated Covid-19 sample for Buffy. (Heat is applied to the Covid samples to deactivate them, so they're no longer contagious to humans or dogs).

"These dogs have about 6 million scent cells in their noses, which is about six or seven times that of humans," Southeastern Guide Dogs CEO Titus Herman said in an interview with WUSF. "They can detect scents even when they are exhaling."

According to Doctors Hospital's chief nursing officer Todd Harner, other hospitals have reached out to learn more about Buffy and find out how to implement a similar program into their facilities. However, extensive training, accuracy and expense are all factors for hospitals to consider before making the practice mainstream.

And when there's a lull in hospital visitors on a given day, Buffy sticks around to provide emotional support to patients and employees.

Welsby says Buffy is not supposed to interact with visitors or people in the lobby unless screening them, but she still manages to cheer them up and make them smile.

Fun fact: Meade adopted Buffy and brings her to work as much as he can. He continues to practice with her at home, using shoes and a deactivated Covid sample in his garage. During her off-hours, Meade says she is a normal, sweet and loving dog.

"The employees are absolutely crazy about Buffy," says Meade. When the hospital was given this opportunity by Southeastern Guide Dogs, Meade knew it would be like pet therapy.

"The staff, and everyone, has become stressed from Covid. But seeing a wagging tail coming toward you down the hallway sure helps," he says.