A photographer tested the concentration of several pairs of dogs as he captured their reactions to treat time in a series of shots. Christian Vieler, 47, of Waltrop, Germany, has been a professional dog photographer since 2016. He came up with the idea of snapping two dogs catching treats simultaneously. Here: Basset Hounds. (Photo by Vieler Photography/Caters News Agency)

A dog jumps into the pool during the Flying Dogs competition in Kamnik, Slovenia, September 10, 2016. (Photo by Srdjan Zivulovic/Reuters)

A dog wearing a Captain America costume, walks on a leash at the “Blocao” dog carnival parade in Rio de Janeiro, Brazil, Saturday, February 18, 2023. (Photo by Silvia Izquierdo/AP Photo)

Prince Dudeman stands on Ryan Thor's head at the 14th annual Helen Woodward Animal Center “Surf-A-Thon” where more than 70 dogs competed in five different weight classes for “Top Surf Dog 2019” in Del Mar, California, U.S., September 8, 2019. (Photo by Mike Blake/Reuters)

Two Corgi dogs collide as they cross the finish line during the SoCal “Corgi Nationals” championship at the Santa Anita Horse Racetrack in Arcadia, California on May 27, 2018. The event saw hundreds of Corgi dogs compete for the fastest dog title at the 17 race event. (Photo by Mark Ralston/AFP Photo)

These adorable pawtraits seem to show the personalities of a variety of canines, capturing their incredible diverseness in their expressions and fine details. Khokhlov and Ershova, who are from Moscow, have taken portraits of about 50 breeds of pooches – earning much critical acclaim. (Photo by Alexander Khokhlov/Veronica Ershova/Caters News Agency)

Magira, the cat, stands in a new pet cleaning machine known as the PetSpa June 21, 2002 in Miami, Florida. The side-loading washing machine features 37 spray nozzles and is capable of washing, rinsing and blow drying a dog or cat in 30 minutes. (Photo by Joe Raedle/Getty Images)

A Border Collie competes in the Flyball during The World Dog Games at Acer Arena on October 31, 2009 in Sydney, Australia. (Photo by Brendon Thorne/Getty Images)