His accuracy, observed in 25 US cases, has led the staff to call family members once he has chosen someone. It usually means they have less than four hours to live.
"He doesn't make too many mistakes. He seems to understand when patients are about to die," said Dr David Dosa.
He describes the phenomenon in a poignant essay in the New England Journal of Medicine.
"Many family members take some solace from it. They appreciate the companionship that the cat provides for their dying loved one," said Dosa, a geriatrician and assistant professor of medicine at Brown University.
The two-year-old feline was adopted as a kitten and grew up in a dementia unit at the Steere House Nursing and Rehabilitation Centre. The facility treats people with Alzheimer's, Parkinson's disease and other illnesses.
After about six months, the staff noticed Oscar would make his own rounds, just like the doctors and nurses. He would sniff and observe patients, then sit beside people who would end up dying in a few hours.
Dosa said Oscar seems to take his work seriously and is generally aloof.
"This is not a cat that's friendly to people," he said.
Oscar is better at predicting death than the people who work there, said Dr Joan Teno of Brown University, who treats patients at the nursing home and is an expert on care for the terminally ill
She was convinced of Oscar's talent when he made his 13th correct call. While observing one patient, Teno said she noticed the woman was not eating, was breathing with difficulty and that her legs had a bluish tinge, signs that often mean death is near.
Oscar would not stay inside the room though, so Teno thought his streak was broken.
Instead, it turned out the doctor's prediction was roughly 10 hours too early.
Sure enough, during the patient's final two hours, nurses told Teno that Oscar joined the woman at her bedside.
Doctors said most of the people who get a visit from the sweet-faced, grey-and-white cat are so ill they probably do not know he is there, so patients are not aware he is a harbinger of death.
Most families are grateful for the advanced warning, although one wanted Oscar out of the room while a family member died. When Oscar is put outside, he paces and meows his displeasure.
No one is certain if Oscar's behaviour is scientifically significant or points to a cause. Teno wonders if the cat notices telltale scents or reads something into the behaviour of the nurses who raised him.
Nicholas Dodman, who directs an animal behavioural clinic at the Tufts University Cummings School of Veterinary Medicine and has read Dosa's article, said the only way to know is to carefully document how Oscar divides his time between the living and dying.
It is possible his behaviour could be driven by self-centred pleasures like a heated blanket placed on a dying person, Dodman said.
Nursing home staffers are not concerned with explaining Oscar, so long as he gives families a better chance at saying goodbye to the dying.
Oscar recently received a wall plaque publicly commending his "compassionate hospice care."
i found this very interesting i just hope this cat doesn't turn up at my place lol