In Werner Herzog's 2010 documentary Happy People: A Year in the Taiga, a dog is reported to run 150 km from the Taiga back to the owner's village, without any stop and seemingly at full speed as it is running next to a snowmobile.
I am skeptical of this. I cannot find any reports of dogs running a distance even close to this. This article on super-distance dogs does not mention any distances over 40 miles (64 km), which is still less than half the distance, and together with the owner running, so at much lower speed.
Can a dog really run 150 km at full speed?