Are Dogs’ Mouths Cleaner Than Humans’ Mouths?

Published Oct. 28, 2021

Many people believe that dogs’ mouths are cleaner than humans’ mouths. This belief has been around for a long time, but is there any truth behind it?

Find out how clean a dog’s mouth actually is, whether their saliva can cause infections and skin rashes in people, and how to keep your dog from licking you so much.

Is Your Dog's Mouth Cleaner Than Yours?

Unfortunately, the answer is no. A dog’s mouth and a human’s mouth both contain billions of bacteria belonging to roughly 700 different species.

Although we both have bacteria in our mouths, the bacteria in a dog’s mouth are mostly different species than the bacteria that inhabit a person’s mouth. These bacteria prefer a dog to be the host, and thankfully, they are not harmful to people.

However, there are similarities between the mouths of dogs and people. For instance, Porphyromonas is the bacterial family that causes periodontal disease in both dogs and people.

The first stage of periodontal disease is gingivitis, which means inflammation of the gums. Gingivitis is caused by bacteria in the mouth that form dental plaque. Billions of bacteria slowly build up on the surface of the teeth, which eventually leads to bad breath, gum recession, tooth root abscesses, and the destruction of bone around the tooth roots.

Early stages of periodontal disease are treatable for both dogs and people with at-home dental care, and just like people, dogs need their teeth professionally cleaned periodically.

Can You Get Infections and Diseases From Dog Saliva?

Dogs can transmit bacterial infections and viral infections through their saliva. However, the overall risk of pathogens being transmitted from a dog’s saliva to a person is very low.

These can be transmitted through your skin if a dog bites you, and if your dog’s saliva were to get into your nose, mouth, or eyes, then these body parts could also absorb the saliva and any pathogens it carries.

Bacterial Infections

The most common bacteria in a dog’s mouth is Pasteurella canis. It’s also the most common organism found in a person’s skin who has been bitten by a dog. Dogs can also transmit a bacteria called Capnocytophaga canimorsus through a bite wound, which can lead to a serious bacterial infection in people.

However, the severity of a bite wound depends on the wound’s location and whether the person is immunocompromised or vulnerable, a group that includes children under 5, adults over 65, pregnant women, and those who are immunocompromised due to a disease process.

If you get bitten by a dog, clean the wound well with soap and water for 15 minutes, and seek medical attention, no matter how minor the wound may look.

Also, if your dog eats food that happens to be contaminated with Salmonella or E. coli, then these pathogens could pass to you if your dog’s slobber gets into your mouth. A raw food diet is more likely to become contaminated, but any dog food can get contaminated with Salmonella or E. Coli.

Rabies (Viral Infection)

Rabies is the most serious infection that dogs can transmit through their saliva. It is a virus that spreads when an infected dog bites a person.

The virus invades the nervous system and leads to a variety of symptoms. Dogs may initially show signs of anxiety and nervousness. Later stages cause dogs to become aggressive, uncoordinated, and disoriented, and they can attack random objects and develop tremors and seizures.

If you see a dog (or wild animal) displaying these symptoms, call your local animal control or police department and stay away from the animal. Rabies is almost always fatal when a dog, person, or any wild animal develops symptoms of this disease.

Is Dog Saliva Bad For Your Skin?

There is not much of a risk of infection if a dog licks your skin (as long as they are not licking a wound) because your skin does a poor job of absorbing saliva.

Some people are allergic to a dog’s saliva, but usually this happens with certain breeds of dogs rather than all dogs. If you are allergic to dog saliva, your skin can break out in hives, develop a rash, and/or become very itchy.

Is Dog Saliva Harmful to Babies?

Although the risk of being infected from dog saliva is low, the most susceptible people are children under 5 years of age, adults over 65 years of age, pregnant women, people without a functional spleen, or immunocompromised individuals.

If you are in one of these categories, then it is best to avoid all contact with dog saliva. If you have a child under 5, never leave them unsupervised around your dog. You can prevent your dog from licking your child by picking your child up so they are out of reach. You can also divert your dog’s attention by giving them a toy to play with, letting your dog outside, or keeping them in a different room when necessary.

How to Keep Your Dog From Licking You

If you are allergic to dog slobber or are immunocompromised, it’s important to train your dog not to kiss or lick you. This can be challenging, but training is key. If your dog tries to lick you, get up and walk away. It is best to ignore your dog when they do this, as this will teach them that licking you will not give them any rewards (e.g., your attention or treats).

If you have any open wounds caused by trauma, you should also prevent your dog from licking at them, because a dog’s saliva can cause your wounds to get infected. If you have a wound, keep it covered with clothing or a bandage to protect it from your dog’s saliva.

How to Keep Your Dog's Mouth Clean

Here are the best ways to keep your dog’s teeth and mouth as clean as possible and eliminate bad breath:

  • Brush your dog’s teeth 2-3 days a week or more using dog toothpaste
  • Sprinkle dog dental powder on your dog’s food at every meal
  • Try a dental water additive made for dogs
  • Ask your vet about prescription dental diets for dogs
  • Give your dog dental treats that have the Veterinary Oral Health Council’s Seal of Acceptance
  • Schedule regular veterinary dental cleanings


Featured Image:

Michelle Diener, DVM


Michelle Diener, DVM


I live in Raleigh, North Carolina. I obtained by BS degree in Biology at UNC-Chapel Hill in 2000 and my DVM degree at NCSU in 2006. I have...

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