Dr. Neilanjan Nandi, an assistant professor of medicine at Drexel University College of Medicine in Philadelphia, says a dog’s saliva has proteins that may help cleanse or heal its own wounds
In a paragraph titled “Why Not to Make Out With Your Pet,” he noted, “There are some organisms unique to dogs that we were simply not meant to tolerate or combat.”
Some common zoonotic bacteria include clostridium, E. coli, salmonella and campylobacter, which can cause severe gastrointestinal disease in humans, said Dr. Leni K. Kaplan, a lecturer of community practice service at Cornell University’s College of Veterinary Medicine.
When dog saliva touches intact human skin, especially in a healthy person, it is extremely unlikely to cause any problems, as there will be very little absorption through the skin,
However, a dog’s saliva and pathogens can be absorbed more easily through the mucous membranes of a person’s nose, mouth and eyes. Though illnesses transmitted this way are rare, Dr. Kaplan said it was best to avoid having your dog lick those parts of your face.