I think there are at least 2 different phenomena involved here. There is a common belief that animals frequently undergo changes in behaviour days before an earthquake is due to hit. This is a poorly understood and possibly not even genuine phenomenon, it has plenty of anecdotal evidence but little hard evidence. I don't want to be too much of a well poisoner but one of the primary proponents of this phenomenon is Rupert Sheldrake, who has a number of batty ideas about animals and their apparently paranormal abilities.
The other is what we see in the video, this dog isn't reacting to the quake days in advance but only seconds. I think this sort of response is possibly adequately explained by the idea of some animals having a broader range of hearing than humans and being able to detect the infrasound that accompanies the earthquake.
As you say though there is no definite mechanism known, just a few competing theories.
TTFN,
WK