As John Oxford, emeritus professor of virology and bacteriology at Queen Mary University in London, recently explained to The Hippocratic Post: “It is not just what is carried in saliva. Dogs spend half of their life with their noses in nasty corners or hovering over dog droppings so their muzzles are full of bacteria, viruses and germs of all sorts.”
But can this cause any problems?
A woman from the United Kingdom found out the hard way. After contracting an infection from her Italian greyhound’s saliva, she ended up in intensive care for weeks with multiple organ failure.
The story of her so-called “lick of death” was told in a recent BMJ Case Report. It began when she reported having slurred speech while she was on the phone with a relative, which prompted her to call an ambulance. By the time paramedics got there, she was found slumped in her armchair losing consciousness. She reached the hospital, where she regained consciousness and her condition improved. She reported no other symptoms, apart from a bad headache the night before.
After four days, however, her condition slipped again and she began suffering from confusion, headaches, diarrhea, a high fever, and her kidneys began to fail. She went on to suffer from reduced liver function and respiratory failure. She was moved to intensive care when it became clear she was suffering from severe sepsis, commonly known as blood poisoning.
Blood tests showed the presence of an infection from Capnocytophaga canimorsus bacteria. Although rare, this bacterium is found in the mouths of cats and dogs. However, the woman showed no bite or scratch marks, leading the doctors to believe the transmission was through a lick from her Italian greyhound.
Although it is worth noting the lady was in her seventies, she had no underlying immune dysfunction. She had to spend two weeks in intensive care, until her infection was cleared through a treatment of antibiotics.
"There have only been about 13 cases reported in the entire United Kingdom, and I'm guessing on a similar scale in the U.S.," said Shelley Rankin, associate professor of microbiology at Penn Vet, to CBS News. "In support of all things furry, this is a normal flora in the mouth of dogs."
Dr. Bruce Farber, chief of infectious diseases at North Shore University Hospital, added: "The last thing you want to do is alarm people that they'll be infected if they get licked or kissed by a dog."
So, while it’s worth considering that there can be some nasty things lurking in your dog's mouth, pooch-smooches are hardly always a death sentence.