The elderly woman died in Melbourne's Box Hill Hospital in May after falling into a coma for over a week, with doctors diagnosing her with bacterial meningitis.
The Herald Sun reports the woman was scratched by her pet cat Minty.
The cat, who slept in the same bed as the woman, then licked the wounds and transferred the deadly bacteria.
Her family found the grandmother unresponsive in bed while her cat slept nearby.
She was rushed to Box Hill Hospital in a coma and doctors detected the presence of pasteurella multocida, a bacteria that can cause bacterial meningitis.
She spent nine days in a coma before regaining consciousness for "beautiful" time with her family before she died one day after being taken off life support.
Lindsay Grayson, director of infectious diseases at Melbourne's Austin Health, told the Herald Sun that people should not let cats lick open wounds and those with compromised immune systems should avoid cats altogether.
"It is a big deal and it is emerging more and more now as an unrecognised cause of heart valve infection, which is obviously fatal if untreated," Grayson said.
"Infections related to cat bites and scratches like this person, we'd get at least one a week where somebody comes into the hospital. It is very important that if a cat is biting or scratching you, you mention it to your GP."
The woman's daughter spoke out to warn other of the danger and admitted that she has struggled with the cat since her mother's death.
"I was in shock for a good couple of weeks. I've tried not to hate the cat … but then I was sitting with it trying to be nice and it lashed out at me as well for no reason."
