A health worker collects a sample screened by a dog that has been trained to sniff out the coronavirus disease (COVID-19), at Chulalongkorn University, in Bangkok, Thailand May 21, 2021. REUTERS/Jorge Silva

A health worker collects samples screened by dogs that have been trained to sniff out the coronavirus disease (COVID-19), at Chulalongkorn University, in Bangkok, Thailand May 21, 2021. REUTERS/Jorge Silva

A health worker collects samples screened by dogs that have been trained to sniff out the coronavirus disease (COVID-19), at Chulalongkorn University, in Bangkok, Thailand May 21, 2021. REUTERS/Jorge Silva

A dog that has been trained to sniff out the coronavirus disease (COVID-19), screens sweat samples at Chulalongkorn University, in Bangkok, Thailand May 21, 2021. REUTERS/Jorge Silva

A dog that has been trained to sniff out the coronavirus disease (COVID-19), screens sweat samples at Chulalongkorn University, in Bangkok, Thailand May 21, 2021. REUTERS/Jorge Silva

A dog that has been trained to sniff out the coronavirus disease (COVID-19), screens a sweat sample at Chulalongkorn University, in Bangkok, Thailand May 21, 2021. REUTERS/Jorge Silva

A dog that has been trained to sniff out the coronavirus disease (COVID-19), screens a sweat sample at Chulalongkorn University, in Bangkok, Thailand May 21, 2021. REUTERS/Jorge Silva

A dog that has been trained to sniff out the coronavirus disease (COVID-19), screens a sweat sample at Chulalongkorn University, in Bangkok, Thailand May 21, 2021. REUTERS/Jorge Silva

A dog that has been trained to sniff out the coronavirus disease (COVID-19), screens a sweat sample at Chulalongkorn University, in Bangkok, Thailand May 21, 2021. REUTERS/Jorge Silva TPX IMAGES OF THE DAY

A dog that has been trained to sniff out the coronavirus disease (COVID-19), screens a sweat sample at Chulalongkorn University, in Bangkok, Thailand May 21, 2021. REUTERS/Jorge Silva

A dog that has been trained to sniff out the coronavirus disease (COVID-19), sits after identifying a positive case, at Chulalongkorn University, in Bangkok, Thailand May 21, 2021. REUTERS/Jorge Silva

A dog that has been trained to sniff out the coronavirus disease (COVID-19), screens a sweat sample at Chulalongkorn University, in Bangkok, Thailand May 21, 2021. REUTERS/Jorge Silva

Dogs that have been trained to sniff out the coronavirus disease (COVID-19), are seen at Chulalongkorn University, in Bangkok, Thailand May 21, 2021. REUTERS/Jorge Silva

A health worker collects samples screened by dogs that have been trained to sniff out the coronavirus disease (COVID-19), at Chulalongkorn University, in Bangkok, Thailand May 21, 2021. REUTERS/Jorge Silva

A dog that has been trained to sniff out the coronavirus disease (COVID-19), screens sweat samples from health workers, at Chulalongkorn University, in Bangkok, Thailand May 21, 2021. REUTERS/Jorge Silva

U.S. First Lady Jill Biden pets Chewy, ATF's National Canine Division member (Bureau of Alcohol, Tobacco, Firearms and Explosives), as she makes her way to board a plane before departing from Albuquerque International Sunport in Albuquerque, New Mexico, U.S. April 23, 2021. Mandel Ngan/Pool via REUTERS

U.S. First Lady Jill Biden pets Chewy, ATF's National Canine Division member (Bureau of Alcohol, Tobacco, Firearms and Explosives), as she makes her way to board a plane before departing from Albuquerque International Sunport in Albuquerque, New Mexico, U.S. April 23, 2021. Mandel Ngan/Pool via REUTERS

U.S. First Lady Jill Biden pets Chewy, ATF's National Canine Division member (Bureau of Alcohol, Tobacco, Firearms and Explosives), as she makes her way to board a plane before departing from Albuquerque International Sunport in Albuquerque, New Mexico, U.S. April 23, 2021. Mandel Ngan/Pool via REUTERS

An officer from the Hennepin County Sheriff's office and his canine partner stand outside the Hennepin County Government Center on the fourth day in the trial of former police officer Derek Chauvin, who is facing murder charges in the death of George Floyd, in Minneapolis, Minnesota, U.S., April 1, 2021. REUTERS/Nicholas Pfosi

A disabled dog is seen next to canine mobility aids before a daily walk at The Man That Rescues Dogs Foundation in Chonburi, Thailand, January 28, 2021. Picture taken January 28, 2021. REUTERS/Athit Perawongmetha

A trainer from the canine service of Aeroflot airline trains sniffer dogs to detect the coronavirus in biomaterial from infected people near Sheremetyevo International Airport, outside Moscow, Russia October 9, 2020. REUTERS/Tatyana Makeyeva

A trainer from the canine service of Aeroflot airline trains a sniffer dog to detect the coronavirus in biomaterial from infected people at a range near Sheremetyevo International Airport, outside Moscow, Russia October 9, 2020. REUTERS/Tatyana Makeyeva

A trainer from the canine service of Aeroflot airline trains sniffer dogs to detect the coronavirus in biomaterial from infected people near Sheremetyevo International Airport, outside Moscow, Russia October 9, 2020. REUTERS/Tatyana Makeyeva

A sniffer dog is trained to detect the coronavirus in biomaterial from infected people at a range of the canine service of Aeroflot airline near Sheremetyevo International Airport, outside Moscow, Russia October 9, 2020. REUTERS/Tatyana Makeyeva

A trainer from the canine service of Aeroflot airline trains a sniffer dog to detect the coronavirus in biomaterial from infected people near Sheremetyevo International Airport, outside Moscow, Russia October 9, 2020. REUTERS/Tatyana Makeyeva

A trainer from the canine service of Aeroflot airline trains a sniffer dog to detect the coronavirus in biomaterial from infected people near Sheremetyevo International Airport, outside Moscow, Russia October 9, 2020. REUTERS/Tatyana Makeyeva

A trainer from the canine service of Aeroflot airline trains a sniffer dog to detect the coronavirus in biomaterial from infected people near Sheremetyevo International Airport, outside Moscow, Russia October 9, 2020. REUTERS/Tatyana Makeyeva

A trainer from the canine service of Aeroflot airline trains a sniffer dog to detect the coronavirus in biomaterial from infected people near Sheremetyevo International Airport, outside Moscow, Russia October 9, 2020. REUTERS/Tatyana Makeyeva

A trainer from the canine service of Aeroflot airline trains sniffer dogs to detect the coronavirus in biomaterial from infected people near Sheremetyevo International Airport, outside Moscow, Russia October 9, 2020. REUTERS/Tatyana Makeyeva TPX IMAGES OF THE DAY

A search and rescue team from Salt Lake City, Utah, including a canine, look for victims through gutted homes in the aftermath of the Almeda fire in Talent, Oregon, U.S., September 13, 2020. Picture taken with a drone. REUTERS/Adrees Latif

A search and rescue team, including a canine, from Salt Lake City, Utah, look for victims through gutted homes in the aftermath of the Almeda fire in Talent, Oregon, U.S., September 13, 2020. Picture taken with a drone. REUTERS/Adrees Latif

A member of a search and rescue team from Salt Lake City, including a canine named Kya, look for victims through gutted homes in the aftermath of the Almeda fire in Talent, Oregon, U.S., September 13, 2020. REUTERS/Adrees Latif

A member of a search and rescue team from Salt Lake City, including a canine named Kya, look for victims through gutted homes in the aftermath of the Almeda fire in Talent, Oregon, U.S., September 13, 2020. REUTERS/Adrees Latif

A member of a search and rescue team from Salt Lake City, including a canine named Kya, look for victims through gutted homes in the aftermath of the Almeda fire in Talent, Oregon, U.S., September 13, 2020. REUTERS/Adrees Latif TPX IMAGES OF THE DAY

A search and rescue team, including a canine, from Salt Lake City, Utah, look for victims through gutted homes in the aftermath of the Almeda fire in Talent, Oregon, U.S., September 13, 2020. Picture taken with a drone. REUTERS/Adrees Latif TPX IMAGES OF THE DAY

A search and rescue team, including a canine, from Salt Lake City, Utah, look for victims through gutted homes in the aftermath of the Almeda fire in Talent, Oregon, U.S., September 13, 2020. Picture taken with a drone. REUTERS/Adrees Latif

Members of an all-female group of canine rescuers from the Italian School of Rescue Dogs (La Scuola Italiana Cani Salvataggio) attend a training session with their dogs before patrolling the beach to ensure swimmers can enjoy their time at the sea in safety, in Riva dei Tarquini, near Rome, Italy, August 25, 2020. REUTERS/Guglielmo Mangiapane

A rescue dog shakes water off as all-female group of canine rescuers from the Italian School of Rescue Dogs (La Scuola Italiana Cani Salvataggio) attend a training session with their dogs before patrolling the beach to ensure swimmers can enjoy their time at the sea in safety, in Riva dei Tarquini, near Rome, Italy, August 25, 2020. REUTERS/Guglielmo Mangiapane

A member of an all-female group of canine rescuers from the Italian School of Rescue Dogs (La Scuola Italiana Cani Salvataggio) attends a training session with her dog before patrolling the beach to ensure swimmers can enjoy their time at the sea in safety, in Riva dei Tarquini, near Rome, Italy, August 25, 2020. REUTERS/Guglielmo Mangiapane TPX IMAGES OF THE DAY

A member of an all-female group of canine rescuers from the Italian School of Rescue Dogs (La Scuola Italiana Cani Salvataggio) attends a training session with her dog before patrolling the beach to ensure swimmers can enjoy their time at the sea in safety, in Riva dei Tarquini, near Rome, Italy, August 25, 2020. REUTERS/Guglielmo Mangiapane

A member of an all-female group of canine rescuers from the Italian School of Rescue Dogs (La Scuola Italiana Cani Salvataggio) attends a training session with her dog before patrolling the beach to ensure swimmers can enjoy their time at the sea in safety, in Riva dei Tarquini, near Rome, Italy, August 25, 2020. REUTERS/Guglielmo Mangiapane

Lifejackets for dogs are seen at the Italian School of Rescue Dogs (La Scuola Italiana Cani Salvataggio) headquarters before an all-female group of canine rescuers start patrolling the beach to ensure swimmers can enjoy their time at the sea in safety, in Riva dei Tarquini, near Rome, Italy, August 25, 2020. REUTERS/Guglielmo Mangiapane

A member of an all-female group of canine rescuers from the Italian School of Rescue Dogs (La Scuola Italiana Cani Salvataggio) attends a training session with her dog before patrolling the beach to ensure swimmers can enjoy their time at the sea in safety, in Riva dei Tarquini, near Rome, Italy, August 25, 2020. REUTERS/Guglielmo Mangiapane

A tattoo in pictured on the shoulder of a member of an all-female group of canine rescuers from the Italian School of Rescue Dogs (La Scuola Italiana Cani Salvataggio) as she gets ready to attend a training session with her dog before patrolling the beach to ensure swimmers can enjoy their time at the sea in safety, in Riva dei Tarquini, near Rome, Italy, August 25, 2020. REUTERS/Guglielmo Mangiapane

An all-female group of canine rescuers from the Italian School of Rescue Dogs (La Scuola Italiana Cani Salvataggio) attend a training session with their dogs before patrolling the beach to ensure swimmers can enjoy their time at the sea in safety, in Riva dei Tarquini, near Rome, Italy, August 25, 2020. REUTERS/Guglielmo Mangiapane

Members of an all-female group of canine rescuers from the Italian School of Rescue Dogs (La Scuola Italiana Cani Salvataggio) attend a briefing before a training session with their dogs and later patrolling the beach to ensure swimmers can enjoy their time at the sea in safety, in Riva dei Tarquini, near Rome, Italy, August 25, 2020. REUTERS/Guglielmo Mangiapane

A member of an all-female group of canine rescuers from the Italian School of Rescue Dogs (La Scuola Italiana Cani Salvataggio) gets ready to attend a training session with her dog before patrolling the beach to ensure swimmers can enjoy their time at the sea in safety, in Riva dei Tarquini, near Rome, Italy, August 25, 2020. REUTERS/Guglielmo Mangiapane

An all-female group of canine rescuers from the Italian School of Rescue Dogs (La Scuola Italiana Cani Salvataggio) attend a training session with their dogs before patrolling the beach to ensure swimmers can enjoy their time at the sea in safety, in Riva dei Tarquini, near Rome, Italy, August 25, 2020. REUTERS/Guglielmo Mangiapane

Members of an all-female group of canine rescuers from the Italian School of Rescue Dogs (La Scuola Italiana Cani Salvataggio) get ready to attend a training session with their dogs before patrolling the beach to ensure swimmers can enjoy their time at the sea in safety, in Riva dei Tarquini, near Rome, Italy, August 25, 2020. REUTERS/Guglielmo Mangiapane

A member of an all-female group of canine rescuers from the Italian School of Rescue Dogs (La Scuola Italiana Cani Salvataggio) attends a training session with her dog before patrolling the beach to ensure swimmers can enjoy their time at the sea in safety, in Riva dei Tarquini, near Rome, Italy, August 25, 2020. REUTERS/Guglielmo Mangiapane

An all-female group of canine rescuers from the Italian School of Rescue Dogs (La Scuola Italiana Cani Salvataggio) attend a training session with their dogs before patrolling the beach to ensure swimmers can enjoy their time at the sea in safety, in Riva dei Tarquini, near Rome, Italy, August 25, 2020. REUTERS/Guglielmo Mangiapane

An all-female group of canine rescuers from the Italian School of Rescue Dogs (La Scuola Italiana Cani Salvataggio) attend a training session with their dogs before patrolling the beach to ensure swimmers can enjoy their time at the sea in safety, in Riva dei Tarquini, near Rome, Italy, August 25, 2020. REUTERS/Guglielmo Mangiapane

An all-female group of canine rescuers from the Italian School of Rescue Dogs (La Scuola Italiana Cani Salvataggio) attend a training session with their dogs before patrolling the beach to ensure swimmers can enjoy their time at the sea in safety, in Riva dei Tarquini, near Rome, Italy, August 25, 2020. REUTERS/Guglielmo Mangiapane

A member of an all-female group of canine rescuers from the Italian School of Rescue Dogs (La Scuola Italiana Cani Salvataggio) kisses her dog after they attended a training session before patrolling the beach to ensure swimmers can enjoy their time at the sea in safety, in Riva dei Tarquini, near Rome, Italy, August 25, 2020. REUTERS/Guglielmo Mangiapane

A member of an all-female group of canine rescuers from the Italian School of Rescue Dogs (La Scuola Italiana Cani Salvataggio) gets ready to attend a training session with her dog before patrolling the beach to ensure swimmers can enjoy their time at the sea in safety, in Riva dei Tarquini, near Rome, Italy, August 25, 2020. REUTERS/Guglielmo Mangiapane

A member of an all-female group of canine rescuers from the Italian School of Rescue Dogs (La Scuola Italiana Cani Salvataggio) washes her dog as she gets ready to attend a training session with her dog before patrolling the beach to ensure swimmers can enjoy their time at the sea in safety, in Riva dei Tarquini, near Rome, Italy, August 25, 2020. REUTERS/Guglielmo Mangiapane

Members of an all-female group of canine rescuers from the Italian School of Rescue Dogs (La Scuola Italiana Cani Salvataggio) patrol the beach with their dogs to ensure swimmers can enjoy their time at the sea in safety, in Riva dei Tarquini, near Rome, Italy, August 25, 2020. REUTERS/Guglielmo Mangiapane

A member of an all-female group of canine rescuers from the Italian School of Rescue Dogs (La Scuola Italiana Cani Salvataggio) attends a training session with her dog before patrolling the beach to ensure swimmers can enjoy their time at the sea in safety, in Riva dei Tarquini, near Rome, Italy, August 25, 2020. REUTERS/Guglielmo Mangiapane

Members of an all-female group of canine rescuers from the Italian School of Rescue Dogs (La Scuola Italiana Cani Salvataggio) patrol the beach with their dogs to ensure swimmers can enjoy their time at the sea in safety, in Riva dei Tarquini, near Rome, Italy, August 25, 2020. REUTERS/Guglielmo Mangiapane