Oscar the death predicting cat

Oscar, a cat in a nursing home in the US has become real popular for its ability to predict when patients will pass away. From WebMD:

"I first heard about him from the nurses on the unit," says Dosa, also a geriatrician at Rhode Island Hospital and an assistant professor of medicine at the Warren Alpert Medical School of Brown University, Providence, R.I. "It came to light that he was spending time with patients as they were becoming terminal."

The cat, Dosa says, seems to snap to attention when he senses a patient is about to die. In the essay, for instance, Dosa tells of Oscar arriving at the room of a woman and curling up beside her for more than an hour, purring and paying attention to the patient as the family arrives and the priest gives last rites, then quietly taking his leave minutes after the woman passes away.

"As people would pass, the question [among staff] was always, 'Was Oscar at the bedside?'" Dosa tells WebMD. "And the answer was invariably 'yes.'

So how did Oscar do it? Sixth sense? Is it its ability to pick out a death scent? No one knows for sure but I surely won't want it to be lying on my bed when I sleep at night.