The actor Gene Hackman died from heart disease at his home in New Mexico, most likely a week after his wife, Betsy Arakawa, died from the effects of hantavirus, a rare disease linked to rodents that can cause respiratory failure, the authorities said on Friday.
Alzheimer’s disease was a contributing factor to Mr. Hackman’s death, Dr. Heather Jarrell, New Mexico’s chief medical examiner, said at a news conference to update the public on the investigation, which has been closely watched since the couple were discovered dead late last month.
Mr. Hackman, 95, was found on the floor of the mudroom in the couple’s home, near his cane, while Ms. Arakawa, 65, was found on a bathroom floor, beside a counter with pills scattered about. They were not discovered until eight days after Mr. Hackman’s pacemaker indicated that he had died.
One of the couple’s three dogs was found dead in a crate not far from Ms. Arakawa’s body.
Dr. Jarrell said that the pills found near Ms. Arakawa were thyroid medication and were not associated with her cause of death. She said hantavirus is contracted through exposure to excrement from rodents — primarily one species of mouse — and it can cause flu-like symptoms before progressing to shortness of breath, as well as cardiac and lung failure.
Erin Phipps, a state veterinarian, said the couple’s home had “low risk” of exposure to hantavirus, but that there were signs of rodents in other structures on the property.
Ms. Arakawa was last seen alive on Feb. 11. Sheriff Adan Mendoza of Santa Fe County said she was seen on surveillance video at a pharmacy that afternoon and returned to her home that evening. He said that her email communication ceased after that day.
“Based on the circumstances, it is reasonable to conclude that Ms. Hackman passed away first, with Feb. 11 being the last time that she was known to be alive,” Dr. Jarrell said, using Ms. Arakawa’s married name.
She said Mr. Hackman likely died on Feb. 18 based on the last activity from his pacemaker — eight days before the bodies were found.
Mr. Hackman’s autopsy showed severe heart disease, Dr. Jarrell said, including evidence of prior heart attacks and multiple surgical procedures involving the heart. He tested negative for hantavirus.
The dog that died was an Australian Kelpie mix named Zinna. The dog, who had once been a returned shelter dog, had turned into an “incredible companion under Betsy’s hand,” said Joey Padilla, the owner of a dog boarder and day care company, Santa Fe Tails. Mr. Padilla said he had watched Zinna and Ms. Arakawa’s relationship “flourish” over the years.
Two other dogs, both German shepherds, were found alive on the property.
The surviving dogs, Bear and Nikita, are “healthy and receiving the best care in a familiar environment,” Mr. Padilla said. He said he was waiting to hear from Ms. Arakawa’s lawyer about what to do with them.
Mr. Hackman, a two-time Oscar winner, and Ms. Arakawa, a classical musician who had founded a home goods store in Santa Fe, had rarely been seen in public in recent years, but when they were spotted in their neighborhood they were often walking their dogs or driving with them in the back. Neighbors said the couple brightened up when they met a fellow dog lover.
Mr. Hackman and Ms. Arakawa were famously private, living at the end of a cul-de-sac in a gated community known as Santa Fe Summit, east of the city. Their deaths had left their neighbors puzzled and sad.
The police have said that there was no security camera footage from inside or outside the home. They said they would review data from two cellphones found at the house and try to determine when someone last had contact with the couple. The police had said that the key to what happened could be in toxicology results from the bodies.
Sheriff Mendoza said the police had essentially ruled out carbon monoxide, given that both bodies tested negative for the potentially lethal gas.
