A Moment of Science

Dog Mouth Vs. Human Mouth

Some people believe that a dog's mouth is cleaner than a human's. While this may be true, which mouth is more dangerous to people?

Would you rather be bitten by a dog or by a human? Well, neither of course, but if you had to choose, which would it be? According to a widespread notion, a dog bite is the better choice since a canine mouth is cleaner than a human mouth.

Wash Your Mouth Out!

But is the popular logic true? Well, yes and no. When we talk about the cleanliness of a mouth, we’re really talking about the amount and type of bacteria it contains. The kind of bacteria found in a human mouth and a dog mouth depends on what’s been there recently.

Unlike dogs, humans typically do not eat raw meat, garbage, and small animals. Given a dog that just locked its jaws around a decomposing squirrel, we might say that the dog’s mouth is less clean than a human’s mouth.

Since the squirrel-eating dog may pick up disease-causing bacteria from the dead animal, a bite from that dog may pass on dangerous germs.

Rabies And Immunity

Insofar as a clean mouth means one that is less likely to cause disease, consider that germs tend to be species specific.

Harmful dog germs are usually harmless for humans, unless we’re talking about rabies, a disease that affects dogs and people in equally damaging ways. But generally, humans are immune to most dog germs.

Likewise, human germs probably won’t harm a dog. But human germs can harm humans, of course. So a bite from a human mouth full of harmful bacteria may very well be more damaging than a dog bite, even if the dog’s mouth is full of harmful dog germs.

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  • ProbioticToothFairy

    Please forgive what might seem a merciless plug for Teddy’s Pride, but your post on mouth bacteria in humans and pets is something we spend a lot of time at Oragenics discussing. We are a biopharmaceutical company that engineers natural probiotic products for oral care that promotes oral health in humans and pets. Our blend of probiotic beneficial bacteria actually competes for space and nutrients of other forms of bacteria on the teeth and under the gum line which improves oral health.

  • Ladii_Phresh

    I dont believe that how is that possible when a dog licks it butt and private area i really dont get it…?????

  • Ladii_Phresh

    I dont believe that how is that possible when a dog licks it butt and private area i really dont get it…?????

  • http://twitter.com/stratcat45 Laura

    Ladii_Phresh: The bacteria(if dangerous) that the dogs has from licking will only affect another dog (your immune system would fight it off). Species specific – the harmful bacteria can only affect the same type of animal. Not to say you wouldn't get germs if the dog licked you – but the germs won't hurt you.

  • Anonymous

    “Dogs are only susceptible to dog germs & humans are only susceptible to human germs”…. now that is a load of crap!  First of all, they seem to be referring to ‘germs’ as bacteria.  The majority of ‘germs’ out there fall into a class that’s called “zoonotic”, which means the bacteria are transmissible to humans from animals. To back that up & be exact, out of the 1,415 known to infect humans, 61% are zoonotic…that is a majority! 
    Ok, does that sound too scientific?  Well, put it this way – ever hear of the Black Plague? …it was a zoonotic bacteria, (Yersinia pestis) that was transmitted from animals to humans, killing an estimated 200 MILLION people (approx. 1/3 of Europe!)  
    Ever hear of Anthrax? … zoonotic also. 
    Ever hear of Cat scratch fever, Chlamydia, Cholera, Leptospirosis, Listeria, Lyme disease, Salmonella, Tetanus, Tuberculosis, E.Coli, or MRSA (Methicillin-resistant Staphylococcus aureus) ? …ALL zoonotic bacteria!   So it is extremely foolish to pretend that ‘dog germs are dog germs & people germs are people germs’…. at the risk of sounding oversimplistic, “germs is germs” folks. 

    And if you are going to split hairs and say that by ‘germs’ what they were REALLY referring to were ANY disease-causing pathogens, well that would be even WORSE!  There are many, many fungi, protozoa & other parasites that cause disease which falls under the zoonotic class.  For example, Amoebic dysentery, Babesiosis, Chagas disease, Giardia, Leishmaniasis, Malaria, Rocky Mountain spotted fever, Schistosomiasis, Toxoplasmosis, and Trichinosis.  Plus, animals can transmit some of your less deadly but equally gross parasites such as: hookworm, pinworm, roundworm, screw-worm, tapeworm, whipworm, and ringworm, which isn’t a worm but a fungus.  Oh, and there’s a ‘new kid on the block’ too, the always deadly Mad Cow disease (bovine spongiform encephalopathy) caused by an abnormal protein called a prion, which is not a bacteria, fungus, parasite, OR virus.
    And as far as animal-transmitted viruses… well, there’s the ever-popular rabies.
    That’s bad enough sure, but that’s hardly all… as many as 75% of existing & newly emerging infectious human viruses, including bird & swine flu, several poxes, Dengue fever, Ebola, Equine encephalitis, Hanta virus, Herpes B virus, Lábrea hepatitis, SARS, West Nile virus, and yellow fever are zoonotic.  And let’s not forget the ‘big bad’ … the most feared zoonotic killer – HIV/AIDS (originally a disease of wild African chimpanzees). 

  • http://profile.yahoo.com/SVPRINXMAH4Q3BONGQ4QKJCSDU Julie Green

    DO YOU THINK A RESPONSIBLE OWNER IS GOING TO LET THEIR DOG EVEN MESS WITH RAW MEAT, TRASH, OR EAT A SQUIRREL!!! OF COURSE NOT, CAUSE THEY KNOW IT’S BACTERIA, THAT CAN EVEN HARM THEIR PET!!! OF COURSE THEY’LL TAKE THEIR PET TO THE VET TO HAVE UPDATED VACCINES, DENTAL CLEANING, & SO ON!!! ALSO A RESPONSIBLE OWNER DOESN’T LET THEIR PET BITE ANYONE!!!
    PLAIN & SIMPLE!!!

  • http://profile.yahoo.com/SVPRINXMAH4Q3BONGQ4QKJCSDU Julie Green

    DO YOU THINK A RESPONSIBLE OWNER IS GOING TO LET THEIR DOG EVEN MESS WITH RAW MEAT, TRASH, OR EAT A SQUIRREL!!! OF COURSE NOT, CAUSE THEY KNOW IT’S BACTERIA, THAT CAN EVEN HARM THEIR PET!!! OF COURSE THEY’LL TAKE THEIR PET TO THE VET TO HAVE UPDATED VACCINES, DENTAL CLEANING, & SO ON!!! ALSO A RESPONSIBLE OWNER DOESN’T LET THEIR PET BITE ANYONE!!! PLAIN & SIMPLE!!!

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