Dog owners normally don't worry if their dogs give them a quick lick.
But you may want to give a doggie's kiss a second thought.
A 70-year-old woman from England became ill, first having slurred speech and becoming unresponsive. She was rushed to a hospital where she got better, but then became confused, started having a headache, diarrhea and fever. Her kidneys also started to fail, CBS News reported.
She had sepsis, or blood poisoning, causing her organs to fail.
But why did she become septic?
Doctors finally found what caused it - capnocytophaga canimorsus, a bacteria found in the mouths of pet dogs and cats, according to a new study published in the British Medical Journal.
Patients who have been bitten by an animal can test positive for the bacteria, but this woman had no wounds.
Doctors realized that her dog, an Italian greyhound, had licked her, the study found.
One infectious disease doctor said he's only seen two cases of the deadly lick in 30 years of medicine, CBS News reported.
Another expert said that you shouldn't be alarmed if your animal decides to lick you, that the bacteria is normal in a dog's mouth. Shelly Rankin, an associate professor of microbiology, said that if you're concerned after a bite, scratch or lick from your pet, that you should check with your doctor.
The initial symptoms of the infection are fever, chills, sweats and no energy. The patient also becomes ill rapidly.
The woman was cured after two weeks of intensive care and antibiotics.