“I know he’s having the greatest time,” Karen Hadfield, a hotelier of British and Australian roots who owns an inn where Cactus lives, wrote Wednesday night on the Marathon des Sables’s Facebook page.

The dog is accustomed to the companionship of strangers. He is also a nomad who often travels about 25 miles a day around the area “just for fun” in this Berber region where humans and animals are familiar with long distances, Hadfield wrote.

On Thursday, a…