Facts on Mouth Bacteria in Dogs

While a dog kiss delivers love, it can also deliver a mouthful of bacteria.
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Your dog or puppy explores the world with his mouth. He's not afraid to chomp away at a bacteria-laden dead animal or pile of feces. This behavior contributes to a mouth filled with a variety of different bacteria. Needless to say, when your pooch plants a slobbery wet kiss on you, he may be spreading more than just affection. He may be getting you sick or contributing to dental disease.

Dental Plaque

Dental plaque is common in dogs; a variety of bacterial species are responsible for the growth of plaque. A 2012 study conducted in Japan looked at the different species of bacteria found in dogs and in their owners. It found that the bacteria Porphyromonas gulae, Tannerella forsythia and Campylobacter rectus, frequently found in dogs, were seen less frequently in humans. The bacteria Eikenella corrodens and Treponema denticola were found only in the dogs who had close contact with human owners having the same bacterium.

Common Mouth Flora

In addition to periodontopathic flora, other natural flora bacteria live within your dogs' mouth. Some of these include Klebsiella pneumonia, Escherichia coli, Staphylococcus aureus, Citrobacter freundii, Enterobacter cloacae, Acinetobacter calcoaceticus and various Pasteurella species. While these normal flora do not make your dog sick, entry of these bacteria into an open wound or through a bite can lead to infection. For example, if your dog cuts his foot on a sharp object and then licks the wound, bacteria can enter the wound.

Dog Bites

Rabies is a virus that spreads via saliva. Rabies is not the only concern when it comes to canine dog bite complications; and many of these complications come from normal flora found in a dog’s mouth. Pasteurellosis is caused by the normal flora bacterium Pasteurella. Capnocytophaga canimorsus causes an infection that can lead to septicemia, or blood poisoning. Other infections include streptococcal infections and staphylococcal infections. Typical symptoms of infected dog bites include pain, reddening and swelling of the skin around the area of the bite.


While kisses from your favorite pooch can be a wonderful welcome home, they can also pose health risks. Pats on the head, belly rubs and a game of fetch are safer ways to show your love to your canine companion. Wash your skin after your dog licks you, especially if you have open cuts or scratches.