Dog owners tend to fall into one of two camps: Those who let their pups kiss them on the mouth and those who don’t. Some members of the former group defend their love of sloppy licks by saying a canine’s mouth is no dirtier than a person's. But according to The New York Times, their muzzles actually teem with microorganisms that we, as humans, aren’t designed to battle.

Long story short, it’s not true that dogs’ mouths are more hygienic than ours. They contain as many microbes, and different ones from those that dwell in human saliva. Plus, some of the bacteria are zoonotic, meaning it can be passed from dogs to humans. For example, some common types of canine-transmitted zoonotic bacteria—including clostridium, E. coli, salmonella, and campylobacter—can cause unlucky pet owners to develop gastrointestinal disease.

Meanwhile, dogs often sniff, lick, and eat gross things, including other animals’ fecal matter. It’s rare—but entirely possible—for a canine to transmit an intestinal parasite to its owner by licking them on the face.

Still, this knowledge shouldn’t relegate you to a life without doggy licks. Experts say it’s likely fine for a dog’s tongue to touch your skin, since it won't absorb the saliva. But since a dog’s saliva and pathogens can be absorbed through the nose, mouth, and eyes, you should probably set some limits on face-licking. The occasional kiss probably won’t hurt you—but just to stay safe, make sure your dog is de-wormed, up-to-date on all its vaccinations, and stays away from other animals’ feces (all things you should already be doing as a responsible dog parent).

[h/t The New York Times]

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