dogs

Dallas Seavey poses with his lead dogs Reef (left) and Tide after finishing the Iditarod Trail Sled Dog Race in Nome, Alaska, in March 2016. Seavey denies he administered banned drugs to his dogs in this year's race and has withdrawn from the 2018 race in protest. Mark Thiessen/AP hide caption

Lulu photographed during explosives training. Central Intelligence Agency hide caption

After the 45th Iditarod Trail Sled Dog Race in March, the race board says, several dogs from a single team tested positive for a banned substance. Ellamarie Quimby/AP hide caption

One of the most famous African dog breeds, the basenji is closely related to street dogs found throughout West Africa. Tara Gregg/EyeEm/Getty Images hide caption

At almost 17 inches, this boxer named Brandy had the longest tongue on a dog ever, according to Guinness World Records. She is pictured with owner John Scheid in Sterling Heights, Mich., in 2001. Jamie Charbeneau/AP hide caption

Campylobacter infections are common in dogs, cats and people. joshblake/Getty Images hide caption

Storm, an English golden retriever, rescued a baby deer from the Long Island Sound on Sunday. Mark Freeley/Screenshot by NPR hide caption

Celebrations that include loud fireworks often terrify dogs. Though there's not yet much science to confirm it, some veterinarians and pet owners say CBD, an extract of hemp or marijuana, can ease a pet's fear. Francisco Goncalves/Getty hide caption

Now here's the glamour shot: Martha at rest in the grass. Josh Edelson/AFP/Getty Images hide caption

Researcher Alexandra Horowitz plays with her dogs Finnegan and Upton. She studies how dog's sense of smell influences their view of the world. Vegar Abelsnes/ Courtesy of Alexandra Horowitz hide caption