Is a Dog's Mouth Cleaner Than a Human's Mouth?
Facts And Trivia About Dog Spit
A lot of people believe that a dog’s mouth is cleaner than a human’s because it contains stuff that kills germs. You may have even heard that it’s good for a dog to lick a human wound to kill germs and prevent infection.
While dog saliva contains antibacterial chemicals and can kill some germs on superficial wounds, those benefits only apply to dogs, not people. A dog licks a wound for cleansing purposes, or because it temporarily alleviates the pain.
When you bang your finger with a hammer, you immediately put it in your mouth, don’t you? Why? Any antibacterial benefit provided by the canine saliva is an added bonus for the dog.
As stated earlier, the antibacterial agents in canine saliva can kill some germs on superficial wounds. The key word is “superficial.” If your dog suffers a deep cut or a bite wound, his saliva won’t equal the benefits of a veterinarian prescribed antibiotic.
While dog saliva can bestow some antibacterial benefits upon the dog, it can actually transmit germs, such as E. coli, salmonella, clostridium and campylobacter, to people.
It's What Helps The Food Go Down
A lot of us tend to think of canine saliva as a toxic soup made up of enzymes that begin immediately digesting a mouthful of raw meat. The fact is canine saliva contains no digestive enzymes. Its purpose is strictly that of a lubricant.
In the wild they would rip large chunks of meat from a kill and, since their jaws only move up and down, they cannot grind their food. That, plus competing vigorously for a share of a kill, dogs will swallow meat almost without chewing it. Therefore it is lavishly lubricated by copious amounts of saliva. The food then passes easily through the esophagus and into the stomach.
By contrast, human saliva does contain digestive enzymes that start breaking the food down before it enters the esophagus. Have you ever noticed that the piece of food you swallow has less to it than it did when it went into your mouth?
In another curious twist, canine saliva is slightly more alkaline than human saliva. It’s believed to be the reason why dogs suffer far fewer cavities than humans. The acidic effect of certain bacteria can cause dental enamel to erode, but the alkalinity of canine saliva offsets that.
The Eewww Factor
That doggie kiss can also, depending upon where the dog’s tongue has been recently, transmit parasites such as roundworms. One study I read about concluded that a puppy can carry from 20 million to 30 million roundworm eggs in its intestinal tract.
I further read about a veterinarian in North Carolina who said that a child of one of his clients almost lost an eye from a roundworm infection. While instances such as that are undoubtedly rare, stuff happens.
Because dogs lick the places on their bodies that they lick, it’s quite common for dogs to have traces of fecal matter in their mouth. Then they want to give you a big, wet kiss.
Medical Issues Associated With Licking
Licking can sometimes become excessive and lead to lick granulomas. Also known as acral lick dermatitis, these self-inflicted wounds can become a nightmare.
In severe cases where the dog’s licking increases the depth of the sore, the skin is affected so deeply that it can result in lesions from microscope pockets of bacteria, broken hair follicles, damaged oil glands and damaged capillaries.
Those lesions can be removed surgically but, unless you can prevent him from licking the surgical site, the dog will likely lick that as well, creating a new granuloma.
Licking Can Lead To Canine Mental Health Issues
Dogs can experience psychological issues that result in obsessive licking. Similar to human obsessive-compulsive disorder, boredom or anxiety can manifest itself in licking, or sometimes scratching and chewing behaviors.
The problem is, if the dog opens up a wound, it doesn’t stop him from continuing those self destructive behaviors, which can cause serious medical conditions.
Human Allergies To Dog And Cat Hair
And how many of you are allergic to dog and cat hair or dander? The correct answer is: none of you. You’re allergic to 12 proteins in the dog’s or cat’s saliva. The hair and dander (shed skin cells) are merely the carriers.
It’s not just the wet saliva that you react to, either. When the saliva dries, those allergenic proteins can become airborne. You can have that allergic reaction even if you don’t come in contact with hair, dander, or a wet tongue.
The Bottom Line
OK, so let’s do a reality check. Millions of sloppy dog kisses are administered to dog lovers every day. I’ll bet that if you could find statistics on the kiss-to-problem ratio, you’d probably discover that the chances of a problem are minimal. But on the other hand, it’s likely that veterinarians and physicians can cite instances of problems they discovered in their own practices.
And I wonder about the number of dog owners who come down with a case of salmonellosis they caught from their dog, but blame it on something they ate or their carelessness with handling raw meat. While some experts acknowledge, but wave off, the dangers of dog kisses, most will frown upon face kisses.
- PetMD: Krystle Vermes: Dog Saliva: Five Fast Fact You Should Know
- Pennsylvania State University, SiOWfa15: Science in Our World: Certainty and Controversy: Does Dog Saliva Have Healing Powers
- Centers for Disease Control and Prevention: Healthy Pets Healthy People: Salmonella Infection
© 2017 Bob Bamberg