My grandmother was schizophrenic, and hated cats. She spent the last ten years of her life extremely ill, and died at 91.
My grandfather, on the other hand, loved cats and always had them. He was healthy as a horse until he died at 104 (and he smoked his own hand rolled cigs and enjoyed his whiskey, health freaks).
My theory based on actual events; if you don't have cats, you don't live as long. :)
Insert "9 Lives" joke here.
The Masters take care of their property.