Why do dogs lick each other’s mouths? Do dogs kiss each other as humans do? You may see your younger dog excitably and obsessively lick an older dog’s mouth, teeth, or face, especially after meals.
Or, sometimes two dogs on a playdate can look like they’re kissing. This is certainly one reason to keep their mouths squeaky clean with natural doggy mouthwash. But the reasons dogs lick other dogs’ mouths are not the same as for humans. In fact, it can be a sign that the other dog makes your dog nervous.
Where a dog chooses to lick another dog is a strong indication of the dynamic between those two dogs. So let’s take a closer look.
So, What Does It Mean When My Dogs Lick Each Other’s Mouths?
A dog licking another dog’s mouth area or teeth is called “appeasement behavior.” Dr. Angelika Firnkes states that appeasement signals are meant to show peaceful intentions and to try to get the other dog to be friendly in return. In this sense, licking behavior also signifies submission to a more dominant dog.
In fact, in one study, dogs reserved licking another dog’s mouth, along with wagging a tail in a low posture and ducking their head under, for most dominant dogs in a pack. So if you’re wondering which dog is the top dog in a situation, take note of which dogs get this body language display from other dogs.
This means a dog sometimes licks the mouth of another dog because they find that dog intimidating, and they’re trying to win them over to ensure they don’t become aggressive.
In other words, it’s a way for a dog to say, “I come in peace; please be nice to me.” So, licking another dog’s mouth signals:
- Respect to a senior pack member;
- A request for a friendly interaction; and
- or can be a way for a young dog to ask an older dog to share their food.
In general, mouth-licking is not affection, although it may lead to affection if the other dog is successfully charmed by it.
Other signals include a dog licking their own lips or nose or averting their gaze, so they don’t make eye contact. This appeasement signal is rooted in puppyhood when puppies lick the mouths of adults to beg them to regurgitate food for them.
Puppy Mouth Licking
If you ever had a young puppy around an older dog, you may have noticed your older dog heaving up whole and undigested food for the younger one. It may be gross to us, but it’s a natural way for older pack members to feed youngsters. So like many peaceful gestures, the reasons dogs “kiss” each other are rooted in puppyhood behaviors.
Unlike wolves, dogs keep many of their puppy behaviors into old age. This includes “kissing” or licking other dogs’ mouths to make friends when they are older.
Why Dogs Love Licking Our Mouths Too
Dogs also love to kiss us on the mouth, particularly when greeting us after we come home. They signal that we are a high-ranking pack member and want to “appease” us into sharing our food and affection.
You may also notice that very friendly dogs often try to lick a stranger in the face and around the mouth when they meet them. This is also a way of signaling that they want to be friends.
If you are wondering if you should return your dog’s kisses, see our article “do dogs like being kissed?“
Why Do Dogs Lick Each Other’s Faces?
When dogs lie down or sit together, they may lick each other’s faces. This is more common with an older dog with a strong maternal or protective instinct toward the younger one. Unlike dogs licking each other mouths, this is not appeasement but affection and grooming.
When dogs lick another dog’s mouth area, you will usually see signs of appeasement. They may:
- Keep their head and body tucked lower than the other dog;
- Keep their tail low, with only the tip wagging;
- Show signs of wanting to roll over and expose belly; and
- Keep the licking to the mouth area only.
However, if both dogs are entirely relaxed together with no obvious signs of appeasing or submission, then face-licking is rooted in affection. Dogs get a rush of endorphins from the process of licking, which is one reason they often lick their paws before bed.
When dogs groom each other, you may see their eyes get droopy and half-closed. Their ear position should be relaxed and neutral. The older or more senior dog will often lick the younger dog’s face. This signifies a deep bond that transcends power dynamics between dogs.
Why Do Dogs Lick Each Other’s Ears?
Dogs lick each other’s ears partly because it helps prevent ear infections and keeps them clean. Dogs are aware of issues such as infections long before we are, as they can smell them. Many canine ear infections start because of Streptococcus spp. Surprisingly, dog saliva can combat this strain of bacteria.
Dogs who are in the habit of grooming each other will lick each other’s ears. This should start with how a mother naturally licks her pup’s ears to clean them. Later, when two dogs have bonded sufficiently to groom each other, ear cleaning is a vital part of the process.
Sniffing each other’s ears is part of a routine health check dogs performs on each other. After all, ear wax has a strong scent, and the glands within the ear canal produce a lot of olfactory data that only other dogs know of.
Furthermore, a dog’s ears are full of nerve endings and blood vessels that make having their ears licked or rubbed feel good. So, the process of ear licking provides both dogs with a rush of endorphins and oxytocin that makes them feel good.
Why Do Dogs Lick Each Other’s Eyes?
Puppies and older dogs are most prone to bacterial eye infections from Streptococcus spp. As with ears, dog saliva is somewhat effective against this bacteria, and so dogs may lick each other’s eyes to clean out gunk and infection.
This is a natural part of the grooming process and facilitates bonding between dogs in the same pack. Remember that even if dogs groom each other thoroughly, their eyes and ears still need to be properly cleaned by us dog owners.
Always make sure you have essentials like eye-cleaning wipes around to keep your dog’s eyes free of debris and pathogens.
Why Do Dogs Lick Each Other’s Privates?
Dogs will sniff and lick each other’s groin or “private” areas because they have an organ in the roof of their mouth for detecting pheromones, called the Jacobson’s organ. Most of a dog’s pheromones come from apocrine glands clustered around the genitals. So by licking these areas, dogs gather essential data about each other.
The rear end also contains the anal sacs, another jackpot for important doggy smells. By licking each other’s genital areas, dogs gather pheromones near the Jacobson’s organ to learn everything they can about another dog’s fertility and health. So it’s really only good manners for dogs to sniff and lick each other in this way.
If a female dog is in heat, this licking of private areas may increase markedly, and even female dogs may do it to one another.
Why Do Dogs Lick Each Other After Drinking Water Or Eating?
Puppies and young dogs will typically lick an older dog’s mouth after they eat or drink water to persuade them to regurgitate their food. You should see this most often between 6 and 16 weeks, but puppies may take their time growing out of this behavior.
If you have a drooler with big globs dripping from their mouth after drinking water, your other dog may lick it up as a simple part of grooming. They may do the same if your dog is a messy eater, but in this case, it’s more likely to lick up the last yummy crumbs if the other dogs will allow it.
Finally, dogs may lick each other after drinking and eating because their bellies are full, and it’s time to rest. Just like a wolf pack will groom each other after they have fed, dogs will often lick each other after eating when the excitement of the day is over, their bellies are full, and it’s time to rest.
Why Do Dogs Lick Each Other After Fighting?
Finally, dogs will lick each other after fighting to make up. However, the dominant dog will rarely lick the other dog. What is more likely to happen is that after a squabble, the more submissive dog will try to lick the mouth of the more aggressive dog to “appease” them.
This is a submissive display meant to show the other dog that is not a threat and to ask for no further fighting. Other appeasement signals include licking their own lips or nose, lowering their body, or tucking their tail. If they can, the submissive dog licks the other dog’s mouth to make up.
Always treat any kind of dog fight seriously. Even if no one is injured, being constantly intimidated and bullied by a more dominant dog can give your submissive dog serious anxiety issues. If necessary, separate them and bring in an experienced dog trainer and behaviorist to help change the dynamic between your dogs.
Final Thoughts
When we wonder, “why do dogs kiss each other?” it’s easy to imagine that it’s just a sign of love and affection. Indeed, when dogs lick each other’s ears, faces, or eyes, it usually is a form of bonding via grooming.
However, licking another dog’s mouth can signify that your dog is nervous that the other dog is aggressive and wants to appease them or show submission. Always keep an eye on this kind of behavior in case a more dominant dog bullies your dog.
Meet Your Experts
Author
Tamsin de la Harpe has nearly two decades of experience with dogs in rescue, training, and behavior modification with fearful and aggressive dogs. She has worked closely with veterinarians and various kennels, building up extensive medical knowledge and an understanding of canine health and physiology. She also spent two years in the animal sciences as a canine nutrition researcher, focusing on longevity and holistic healthcare for our four-legged companions. Tamsin currently keeps a busy homestead with an assortment of rescue dogs and three Bullmastiffs.