“A dog’s mouth is actually cleaner than a human’s mouth” is an oft-repeated adage by dog owners who happily accept their pet’s slobbery affections. However, having seen my own pup go to town on a freshly laid pile of “kibble” the deer left for him in the yard, I highly doubt that.
When he wants to share his love and bestow my face with kisses, I’m in a bit of a bind. On the one hand, he is the light of my life and the most perfect baby boy. How can I tell him “no” when he wants to give me a little affection?
On the other hand, as a skin care writer and former face-toucher, I’m all too aware of how bacteria and other impurities can wreak havoc on our skin.
While the occasional breakout may be a small price to pay for accepting your furry friend’s love and affection, you may remember the 2019 news story in which an Ohio woman lost all four limbs from an infection caused by a kiss from her own puppy.
Although that was a very rare case, should we nevertheless practice caution when allowing our pets to lick our faces? Or is the regular smooch from Fido fairly harmless?
We spoke to experts in the dermatology and veterinary fields to find out more.
How ‘Clean’ Is Your Dog’s Mouth, Actually?
“All mouths are ‘dirty’ in the sense that they are full of microbes,” said Dr. Tessa LeCuyer, an assistant professor and veterinary clinical microbiologist at the University of California, Davis School of Veterinary Medicine.
“A dog’s mouth is not any cleaner than a person’s mouth, as both are full of hundreds of different types of bacteria,” LeCuyer said.
As dogs see the world with their noses, many are drawn to two particularly pungent sources brimming with bacteria and parasites — feces and carrion (aka dead critters). And to their owners’ abject horror, many dogs love to chow down once they find one of these forbidden snacks.
While LeCuyer says that, generally, your dog’s love of “other chocolate snacks” won’t lead to disease, she does note that there are some parasites and bacteria that dogs can pick up from eating feces.
“Dogs can ingest bacteria like salmonella from feces of other animals,” said LeCuyer. “Dogs that eat feces from other dogs are at increased risk for parasites such as roundworms.”
She said the risk of your dog picking up certain pathogens can also depend on which animal’s feces is their treat of choice. “Bird feces are more likely to harbor salmonella than mammalian feces,” LeCuyer said.
It’s no surprise that microscopic nasties could living in an animal corpse that your dog decides to chomp on. However, despite the popularity of feeding dogs raw meat as a part of a “raw food diet” in recent years, this trend could put your dog (and you) at risk of getting sick.
“Ingestion of raw meat, whether carrion or food-grade, increases the risk of exposure to foodborne bacteria such as salmonella and listeria, which can cause disease in dogs as well as people,” LeCuyer said.
Fortunately, LeCuyer says that dog owners can drastically decrease their risk of picking up a disease from their dog with good handwashing hygiene – particularly after handling your pet and/or their poop. And if your dog has a habit of going to the feces and carrion buffet, it may be time to implement a “no kissing on the lips” rule.
“Transfer of bacteria or parasites could potentially occur when a dog licks someone around or in the mouth,” LeCuyer said.
Can The Bacteria In My Dog’s Mouth Harm My Skin?
You already have a highly sophisticated defense system that protects you against any germs living in your dog’s mouth, as well as any other environmental contaminants — your skin.
“Most of the potentially harmful bacteria in a dog’s mouth can only cause disease in a person when there is a break in the skin that allows the bacteria to infect deeper tissues,” LeCuyer said.
Generally, the most common way bacteria from a dog’s mouth can infect the deeper tissues of the skin is if it bites you. Dr. Danielle Dubin, a board-certified dermatologist and assistant professor of dermatology at the Icahn School of Medicine at Mount Sinai, says dog bites on the hands and face, as well as deep bites, are prone to skin infections, particularly for immunocompromised patients.
“It is important to have these types of injuries evaluated by a health care professional to determine if antibiotics are indicated,” Dubin said.
Although it’s far more common to contract a skin infection from a dog bite rather than a dog kiss, our experts still urge exercising caution if your dog tries licking an area where your skin barrier might be weakened.
“If you have any breaks in your skin, such as from rashes, cuts or pimples, the [dog’s] saliva could potentially cause an infection,” said Dr. Jennifer Chen, a board-certified dermatologist and clinical professor of dermatology at Stanford University.
Consider Your Dog’s Smooching Style
When it comes to determining how “bad” it is for your dog to lick your face, think about the way your dog expresses affection. Does Fido give you a quick little peck when you return from a long day at work? Or do they treat your face to their full doggie-spa special?
“A wet kiss or two is unlikely to cause any problems in an otherwise healthy adult with intact skin,” Dubin said. “However, repeated licking, even in [a healthy adult] population, carries a risk of developing irritant contact dermatitis,” Dubin said.
Although your skin can probably withstand a kiss or two from your pup every now and then, constant licking could cause some issues.
“The constant wet-dry cycle of exposure also disrupts the skin barrier,” said Chen. “This can result in a rash consisting of peeling, dry skin that may crack and bleed and become uncomfortable.”
Beyond Bacteria: Other Ways Dog Saliva Can Affect Your Skin
While most are concerned about the bacteria living in their dog’s mouth, that isn’t the only way your dog’s kisses can irritate your skin.
Dubin points out that some individuals could potentially have an allergic reaction to the proteins in their dog’s saliva, resulting in allergic contact dermatitis.
However, even if you aren’t allergic to dogs, Chen notes that saliva itself can be a skin irritant.
Another risk factor, according to Chen, is that your dog may inadvertently pick up and transfer irritants to your skin. So, if your fur-baby particularly loves exploring the neighborhood poison ivy patch, you may think twice before letting them lick your face.
“Sometimes we will also see patients become allergic to their dog’s products,” said Chen.
Who Should Avoid Getting Licked
While people with healthy skin should be OK accepting a slobbery peck from their pup every once in a while, some should exercise more caution.
“[For] patients with pre-existing skin conditions such as acne, rosacea or eczema, dog saliva can trigger disease flares and/or skin-limited infections,” said Dubin.
Our dermatologists also warn that if you have any cuts, rashes or breakouts on your face, you should also hold off on letting your dog lick you.
“Patients who have medical conditions or are on medications that result in a suppressed immune system will also be at higher risk [of infection],” Chen said.
Beware of Skin Care Ingredients That Can Harm Your Pet
Even if you are OK with putting up with the occasional breakout or risking a potential skin infection for the love of your pet, there is one other thing to consider before allowing your dog to kiss you: Certain skin care ingredients can potentially harm dogs if ingested.
“Don’t let your pet lick any topical medications you apply to your skin or hair,” said LeCuyer.
Several skin care ingredients can be harmful to pets, LeCuyer warns. “One of the biggest concerns is xylitol, which can be toxic to dogs even in relatively small amounts and is in many skin care and toothpaste products.”
While many dog owners are well aware of xylitol’s presence in gum and other sugar-free products, they might not realize that this sweetener is also used as a moisturizing agent in some skin care products.
Another common ingredient to look out for is zinc oxide. Though beloved by dermatologists for its ability to gently protect your skin from the sun’s harmful rays, it can trigger stomach upset or an allergic reaction in your pet if they ingest it, according to the American Society for the Prevention of Cruelty to Animals.
Additionally, the ASPCA also warns that there are a number of topical ingredients, including many topical pain relievers like diclofenac, lidocaine and dibucaine, that can cause severe damage or death if ingested, even in small doses (i.e., if your dog licks the area where you applied the topical).
When in doubt, LeCuyer recommends contacting the ASPCA Animal Poison Control Center via their 24/7 hotline, (888) 426-4435.