The most commonly found bacteria in canine saliva are Actinomyces, Streptococcus, and Granulicatella species, reports the Journal of Clinical Microbiology. Cultures of canine plaque also contained Porphyromonas and Neisseria species.
Although scientists often use the canine mouth as a model for human oral hygiene, there are vast differences in the oral bacteria of dogs and humans, notes the Journal of Clinical Microbiology. Of the bacteria that researchers found in dogs' mouths, only 28 percent were similar to the bacteria usually present in the mouths of humans. Variances also occur in dogs of different breeds.
Plaque in dogs' mouths develops from saliva, bacteria, cells from the mouth and food debris, states WebMD. Additionally, dogs can develop tooth problems similar to those in humans, including infections of the teeth and gums. A dog with an infected tooth often shows no signs of pain, but may have difficulty chewing or picking up its food. Redness of the gums, bleeding, loose teeth and bad breath are other signs of dental problems in dogs.
Good dental hygiene is important for dogs, instructs WebMD. Daily tooth-brushing, chew toys, a good diet, and annual oral examinations are all important to maintain the oral health of a dog.