A surveillance camera on a Santiago freeway captured images of a dog trotting past speeding cars to pull the lifeless body of the other canine, which had been run over by a vehicle, away from traffic and onto the median strip.
The scene was broadcast by Chilean television stations and then posted on Web sites such as YouTube, and hundreds of thousands of people had viewed versions of it by Monday.
Highway crews removed both the dead and live dogs from the median strip of the Vespucio Norte Highway shortly after the Dec. 4 incident. But the rescuer dog ran away.
Authorities say images of the rescue prompted some people to call and offer to adopt the dog, but neither highway workers nor a television crew could find the animal.