Dog watching over his owners grave

It reminds me of that Futurama episode: Jurassic Bark.

That dog was actually based on the true Japanese story of Hachiko. But it's a pretty similar case, Hachiko waited every day at the station where his owner used to leave to go work, despite him not coming back after some sort of unexpected illness killed him while he was at work, until the day Hachiko died after almost 9 years.