Should I Kiss My Dog?

We all do it — come home and find our dogs at the door, tails wagging, and looking longingly at us. We swoop down, give them a hug and plant a juicy kiss on their faces, often allowing them to reciprocate with a lick on the nose, cheek, or mouth. But is this sanitary? Can you get sick from kissing your dog? A new study may have you thinking twice about letting your dog lick your face.

Kissing your dog can lead to gum disease

Researchers found disease-causing “peridontopathic” bacteria present in plaque of both the dogs and humans tested. This bacteria is linked to periodontis, a severe form of gum disease which, according to the Pacific Northwest Veterinary Dentist & Oral Surgery Center, causes the destruction of the supporting tissues of the tooth and can lead to heart disease, kidney disease, and diabetes.

Types of bacteria found in the samples

The study revealed that three kinds of disease-causing oral bacteria: Porphyromonas gulae, Tannerella forsythia, and Campylobacter rectus “were frequently found in the dogs, whereas the detection rates of those species in humans were less frequent.” There goes the myth that “your dog’s mouth is cleaner than yours.”

The plaque samples also showed the appearance of Porphyromonas gulae in 13 human subjects and all of their tested dogs. In addition, researchers published that bacteria known as, “Eikenella corrodens and Treponema denticola in specimens obtained from dogs were correlated with their presence in specimens from owners who had close contact with them.” In case the scientific names for the various bacteria are too daunting, the short version is this: they are all know to cause periodontal disease.

We asked Dr. Paul Maza, co-director of the health center at the College of Veterinary Medicine at Cornell University, how close is too close when it comes to your pet?

“Many of the different types of bacteria in dogs and cats are the same type of bacteria as in humans. At any given point in time they are probably not any dirtier than ours,” Maza said.
In fact, Maza said if owners practice oral hygiene on their pets, like with brushing their teeth, a pet’s mouth can actually be even cleaner than a human mouth. “Because most of the bacteria and viruses in a dog’s mouth are the same as in a person’s mouth, it is safe to kiss a dog, just like a person. You can probably catch more from kissing a human than a dog or cat,” he said.

According to the Humane Society, there are approximately 77.5 million owned dogs in the United States and 93.6 million owned cats. Although very unlikely, there are rare instances in which zoonotic diseases, or diseases that are transmitted between animals and humans, can occur. Maza said disease transmission is very rare in cats and even more rare in dogs.

“Cats may have bartonella, or cat scratch fever, that can cause disease in people. Taxolpasmosis, or certain parasites that have eggs in fecal matter — the transmission of parasites can cause disease in people. But again, it doesn’t happen very often, it is unlikely,” he said.

But we had to ask — what about fecal matter in a pet’s mouth? That is their way of taking a shower, after all. Maza said that although the grooming technique of pets can cause fecal bacteria in the mouth, it is often swallowed and out of the mouth quickly. “Fecal matter could be considered comparable to any other normal bacteria,” he said. For many people, kissing a dog or cat may be less of a safety issue and more of a mysophobia issue, or fear of germs.“ A dog licking a baby on the head or hand is probably safe, but some like to avoid germs at all costs. Others say there are germs everywhere and it is too hard to avoid them all the time,” he said.

Those who should think about avoiding a kiss from Fido include anyone with a compromised immune system like those with HIV or other diseases, as well as the elderly. There are debates that a kiss from a dog or cat may be beneficial for the immune system of young children. “Babies that are ill shouldn’t be around too many germs, but others say it is good for children—it stimulates the immune system and establishes early immunity,” Maza said. As far as preventing any possible illness from kissing a pet, Maza recommends “common sense hygiene.”

“Many people will use gloves to clean litter boxes and pick up dog poop, and you can even wash hands after petting. If you want to prevent bacteria of the mouth, you can brush pets mouths and use rinses just like people do,” he said. “Don’t allow pets on kitchen counters and if it can’t be avoided then wipe them of before preparing food.”

Overall, Maza said the mental health benefits of kissing your pet far outweigh the risks of getting sick.