Her business manager, Jerome B. Rosenthal, and husband, Martin Melcher, who died in 1968, had sunk something like $20 million of her earnings into bad investments, most of them in Rosenthal's own companies.
"I've never been one to dwell on the past," she says, "which is lucky. I could still be an angry woman, kicking things. I don't know if Marty betrayed me or not. I tend to think he didn't betray me. I think he loved me."
After the interminable trial, involving more than 100,000 pages of testimony, on her suit against Rosenthal, a court awarded Day $26 million. This was subsequently scaled down to $6 million. It is not a negligible sum but the shock of the deceptions, even if Melcher was himself an unwitting pawn, as she chooses to believe, is not erased.
"It's amazing to think that the house I'd paid for 20 years earlier could've been taken away from me," Day says. "It was that close. Marty in desperation had sold me to CBS for a series I knew nothing about, not even the basic idea.
"I was a wreck. I didn't sleep, couldn't sleep more than an hour at a time for three months. When Marty died I was so fatigued I couldn't brush my own hair; I couldn't lift my arm. I would go for a walk and almost fall to the sidewalk.
"It took me a year to get over his death. And even after his death he was on the set when I worked. I kept thinking I saw him."
In the late '70s she was briefly married for the fourth time, but she and Barry Comden separated after three years.
Having begun her career as a band singer, Day recently started singing again. Just before she did the Robertson series (on which she sang "good news" songs), she had been recording an album of songs written by her producer-composer son Terry, who also sings.
"He sings very well," she says. "I'm such a perfectionist that if I didn't think so, I'd tell him to stay out of it. But he does, and one of these days he's going to have a hit. His other hat is in business. He works with my
accountants and he's a tremendous help to me."
She will get around to finishing the album, she thinks, although her animals appear to be more work than a television series. Her Pet Foundation underwrites the spaying and neutering of animals and finds foster homes for strays after they've been returned to health.
Her Animal League aims to stop abuses in animal experimentation. "I don't think it'll all be eliminated ever; I'm realistic about that," she says. "I'd like to see it all stopped, but at least if the experiments are done the right way, with no abuse, I guess we have to go along with it. I can't bear to see anything suffer. And there's an awful lot of needless experimentation. You need somebody there to watch it all the time."
She would also like to see laws against dogs riding in the back of pickups. "The wind burns their eyes," she says, "and if they're chained so they can't fall off or jump off, they break their necks if there's a wreck."
It is a crusade and she is a crusader, and it is hard to miss the resolve, both steely and passionate, beneath the cheery exterior. "To have the innocents suffer is unthinkable," Doris Day says. "Most people don't know about it. I have to do something about it in my lifetime, get it all out there."
Given the intensity, it's not too surprising to hear that Day would like to do a dramatic role when she returns to the entertainment wars. "Comedy is harder. It's unreal. Drama is reality; it's normal, everyday living."
She would also like to try improvising everything. "The script would say, 'Here's the gist of the scene, now do it.' I'd adore that. I'm spontaneous. I've always liked that first take."
Day does sound like a performer who wouldn't mind getting in camera range again, although she says, "I'm working harder than I've ever worked, and I'm not even working."