Working Dogs for Conservation trainer Michele Vasquez clips a vest onto Charlie, a Labrador retriever, to let him know he's working. Dogs like Charlie will help sniff out chronic wasting disease in deer and elk scat. They will also help find mink and otter droppings that can be tested for toxic substances near illegal dumpsites. Aaron Bolton/Kaiser Health News hide caption
Trumpet, a bloodhound, competes for best in show at the 146th Westminster Kennel Club Dog Show, Wednesday, June 22, 2022, in Tarrytown, N.Y. Trumpet won the title. Frank Franklin II/AP hide caption
K-9 Officer Teddy Santos watches Huntah as she checks a classroom at Freetown Elementary School. If she detects COVID, she will sit. Jodi Hilton for NPR hide caption
Freetown Elementary School students Mason Santos, left, and Mila Talbot, right, pet Huntah the dog after she finishes checking a classroom. Jodi Hilton for NPR hide caption
Yuri Mazurenko and Macha Levitin get ready to go on a walk with their dogs Rolly and Safra in a village in Burgundy, France. Eleanor Beardsley/NPR hide caption
Green the Chow Chow sits in the grooming area at the 142nd Westminster Kennel Club Dog Show at The Piers on February 12, 2018 in New York City. The show is scheduled to see 2,882 dogs from all 50 states take part in this year's competition. Drew Angerer/Getty Images hide caption
Eva relaxes in a puddle in 2020. Erin Wilson hide caption
Patron poses at an award ceremony in Kyiv, Ukraine on Sunday. The Jack Russell terrier is credited with detecting more than 200 Russian explosive devices since the start of the war. Efrem Lukatsky/AP hide caption
A border collie in northern England chases after a flock of sheep to herd them. A new study finds that only about 9% of the variation in an individual dog's behavior can be explained by its breed. Edwin Remsberg/Getty Images hide caption
A Ukrainian pyrotechnic squad works alongside Patron, a bomb-sniffing dog. State Emergency Service of Ukraine hide caption
Shelter animals are also suffering the consequences of the war in Ukraine. This week, volunteers at a shelter outside Kyiv, the capital, found more than 250 malnourished dogs that had survived weeks without food or water but also more than 300 that had starved to death. Rodrigo Abd/AP hide caption
A student's drawing on behalf of Sleigh Ride. St. Michael's Episcopal School/RACC hide caption
With flattened faces, wrinkles and short airways, bulldogs are prone to health problems. A court in Norway banned the breeding of bulldogs unless it's to improve the breed's health. Sarah Stier/Getty Images hide caption
Jaqueline Castro plays with a Schnauzer named Paola at the Support Hospital of Brasilia, Brazil, on Nov. 24, 2016, as part of program set up to help patients with chronic diseases or recovering from trauma. Eraldo Peres/AP hide caption
Recent snow covers the pine trees alongside Interstate 93 as the road enters the White Mountains on December 26, 2021 in New Hampshire. Andrew Lichtenstein/Corbis via Getty Images hide caption