A pet dog dressed in vehicle-style costume participates in a pet dog competition in San Francisco, the United States, on Sept. 14, 2019. The competition was held on Saturday, during which pet dogs showcased vehicle-style costumes and competed in a race. (Photo by Li Jianguo/Xinhua)

Pet dogs dressed in vehicle-style costumes participate in a pet dog competition in San Francisco, the United States, on Sept. 14, 2019. The competition was held on Saturday, during which pet dogs showcased vehicle-style costumes and competed in a race. (Photo by Li Jianguo/Xinhua)

Pet dogs compete during the race session of a pet dog competition in San Francisco, the United States, on Sept. 14, 2019. The competition was held on Saturday, during which pet dogs showcased vehicle-style costumes and competed in a race. (Photo by Li Jianguo/Xinhua)

A dog dressed in vehicle-style costume participates in a pet dog competition in San Francisco, the United States, on Sept. 14, 2019. The competition was held on Saturday, during which pet dogs showcased vehicle-style costumes and competed in a race. (Photo by Li Jianguo/Xinhua)

A pet dog dressed in vehicle-style costume participates in a pet dog competition in San Francisco, the United States, on Sept. 14, 2019. The competition was held on Saturday, during which pet dogs showcased vehicle-style costumes and competed in a race. (Photo by Li Jianguo/Xinhua)