Let's face it: It's pretty hard to resist puppy kisses, even if you know deep down that it's kind of gross.
Every time I go home to visit my parents, I'm greeted by our Labrador mix, Scout, who has to lick my entire face for several minutes before she calms down. As someone who writes a lot about germs, I know that it's probably not the best idea, but feeling loved by a dog is the best feeling ever. Seriously, who doesn't love puppy kisses?
So, is it actually unhealthy to let your dog lick your face?
We spoke to germ expert Kelly Reynolds, associate professor of environmental health at the University of Arizona, to find out if kissing your dog can actually put your health at risk.
First of all, a dog's mouth is not cleaner than a human's mouth — that's a myth.
You might've heard at some point in your life that dogs’ mouths are cleaner than humans — this isn't really true. And it's like comparing apples to oranges. "The bacteria counts tend to be similar but the types of bacteria are very different," Reynolds tells BuzzFeed Health. Humans and dogs each have a unique normal flora of bacterial species in their mouths to keep things in balance.
However, humans generally practice dental hygiene, whereas dogs do not, unless their owner helps out. Dogs have evolved to compensate for the lack of dental care, Reynolds says, but that alone isn’t enough. “That’s why it’s so common for older dogs to have gum disease, tooth decay, and foul breath,” Reynolds says. Not to mention, dogs pick up a lot of nasty germs from the environment. They love getting into gross stuff — whether it's the trash, another animal's poop, dead birds, dirty puddles...the list goes on. "Overall, from a health perspective, dogs' mouths are not cleaner," Reynolds says.
Actually, there are several kinds of bacteria and parasites in dog saliva that can make you pretty sick.
Most of the bacteria in your dog’s mouth are harmless, but there are exceptions. "Dogs can carry a number of zoonotic pathogens, or organisms spread from animals to humans that cause disease," Reynolds tells BuzzFeed Health. You can get these from dog kisses or from contact with infected feces. These include bacteria and parasites, like Salmonella, Pasteurella, Campylobacter, Cryptosporidium, Leptospira, Giardia, ringworm, and hookworm. Yuck.
"Some of these are common causes of diarrheal illness outbreaks in the US," Reynolds says. Just this year, an outbreak of Campylobacter infections in sick puppies spread to 67 people, and 17 were hospitalized.
These pathogens are common, Reynolds says, and your dog can pick them up anywhere — from sniffing other dogs (and their poop), contaminated food or water, streams or ponds — but you can’t always tell when they do. "These can make your dog sick (usually with diarrhea), but oftentimes the dog will carry them asymptomatically," Reynolds says. So you may not even realize that your pup caused your stomach bug. The only way to find out what your dog is carrying is by sending a stool sample to your veterinarian for testing.
These pathogens can infect anyone — sometimes without symptoms — but people with weaker immune systems face a higher risk.
What’s the likelihood of your dog making you sick? "It really depends on your individual health and the dog’s health," Reynolds says. People can also carry some of these bacteria (like Campylobacter) asymptomatically too, Reynold says, so even if your dog spreads them to you it doesn't always mean you'll get sick — especially if you have a robust immune system. But asymptomatic carriers can still infect other people and make them sick.
Immunocompromised people have a higher risk of getting sick from zoonotic pathogens, Reynolds says. These include the elderly, pregnant women, people with HIV/AIDs, people receiving chemotherapy, transplant patients, etc. These people should not let dogs lick their face and should always wash their hands after petting or handling dogs, Reynolds says. If you are concerned about contact with dogs and your health, always talk to your doctor.
And there's no evidence that swapping spit with your dog will improve your immunity.
Yes, dogs will expose people to new and different types of bacteria, Reynolds says, but there’s no evidence that this builds your immunity to any diseases. "Humans can't even gain immunity from some of the pathogens dogs carry, like the parasites for example, so they can just repeatedly infect you," she says. Simply put, humans are not meant to tolerate some of the bacteria dogs carry in their saliva. "It's best to avoid them if you can." You don’t need to stop letting your dog lick you entirely, but you should try to keep your face and any open wounds off-limits.
If you're still going to let your dog lick your face, at least try to avoid getting slobber on your actual mouth, wash your face afterward, and definitely don't do it when your dog is sick.
"The pathogens really enter your body through the mucus membranes on your face — so the mouth, nose, and eyes," Reynolds says. So keep the dog’s tongue away from those areas. And if your dog licks other parts of your face, wash the saliva off with soap and water afterward. You should also wash your hands right after a dog licks them, or at least before touching your face and eating, since this is another way that pathogens can enter your body. "It doesn't matter if it's your dog or someone else's that licked you, you should still wash your face and hands after," Reynolds says.
And seriously, do not let your dog lick your face when it is sick or it has diarrhea. They may look mopey and cute, but just wait until they are better. Same goes if you’re sick or immunocompromised — you can enjoy your dog’s affection, but don’t let them kiss you.
Finally, there are some simple steps you can take as a pet owner to significantly reduce your risk of getting sick from your dog.
It’s very important to practice basic hygiene (like handwashing) after picking up your dog’s poop since you can contract infections from infected feces. You should take extra precautions when your dog has diarrhea, says Reynolds, since your dog is shedding millions of microorganisms in their poop. "Try to isolate the dog so they aren't spreading fecal matter all over the house, don’t let them in your bed, wear gloves when you clean up after them, and always wash your hands after touching them."
As a dog owner, you should keep your pup as healthy as possible, too. We probably don’t need to tell you how to do that, but hey, a reminder doesn’t hurt!