Why do man’s best friends often lick the backs of our legs? This peculiar canine behavior has dog owners everywhere scratching their heads. According to research, up to 85% of dogs exhibit at least one problematic behavior like excessive licking, barking, or aggression [1]. While licking the backs of human knees may seem like an odd quirk to us, it’s actually deeply ingrained in canine instincts.
In this article, we’ll explore the top theories behind why dogs lick the backs of knees. Is it a show of affection? A way for your dog to sample tastes and smells? Or could it signal anxiety, attention-seeking, or a medical issue? We’ll also provide tips on how to curb excessive licking if it becomes bothersome.
It’s a Form of Affection
Licking is a natural behavior for dogs to show affection. When dogs lick each other, it releases pleasurable endorphins. According to the Kennel Club, “Dogs often lick humans to show affection, as a greeting, or to simply get our attention. Licking is pleasurable to dogs.” They often lick their owners as a way to bond with them and show them love [1].
The American Kennel Club notes dogs will often lick their owners’ faces simply because their owner’s face tastes good and brings them comfort [2]. For example, the dog may lick its owner’s face at a time when their owner is giving them attention and affection. Therefore, licking is a way for the dog to reciprocate affection and strengthen their bond.
Scent and Taste
Dogs have an incredibly powerful sense of smell, with up to 300 million scent receptors compared to a human’s 5 million (https://vcahospitals.com/know-your-pet/how-dogs-use-smell-to-perceive-the-world). Their sense of smell is 10,000 to 100,000 times more acute than humans. Dogs can detect scents at concentrations nearly 100 million times lower than humans can. Their sense of taste is also very discerning, with about 1,700 taste buds compared to a human’s 9,000.
The area behind the knees contains concentrated sweat and skin cell secretions that produce a distinct scent and taste profile for each person. With their ultra-sensitive sniffers, dogs can pick up on the unique smells emitted from the sweat glands and sebaceous glands in that area. By licking the back of your knees, your dog is able to get a special scent and flavor experience that allows them to gather information about you. This knee-licking behavior serves several purposes related to your dog’s advanced olfaction abilities.
Submission
Licking is often a submissive behavior for dogs. Dogs will lick the faces and muzzles of more dominant pack members during greetings as a show of submission. Licking the back of your knees forces them into a crouched, submissive posture. According to the American Kennel Club, “One theory is the licking is a sign of submission. The idea is that dogs who are submissive will lick a more dominant member of the pack.” 1
As mentioned on Cuddly Tails, “If a dog licks another dog’s face, they are often signaling that they are not a threat. Face licking in the canine world is also used as a greeting.” 2 When dogs lick the back of your knees, it forces them into a crouched posture which is a very submissive position for them. The licking behavior itself also signals submission in the pack hierarchy.
Grooming
Licking serves an important grooming purpose for dogs. Dog saliva contains antibacterial properties that keep their skin clean and free of germs. Licking can act as a self-soothing, grooming behavior that relaxes the dog. According to https://www.petmd.com/dog/general-health/excessive-licking-chewing-and-grooming-dogs, dogs will often lick their own fur to smooth it down and remove dirt or debris. When they lick human skin, they are essentially trying to groom us as well.
Dogs primarily lick areas that are prone to sweat, like the hands, feet, or legs. The antibacterial agents in their saliva can help cleanse these sweaty areas. Much like their innate instinct to lick their own wounds, dogs may lick human wounds or irritated skin in an attempt to clean it or improve healing. So some licking of human skin is normal grooming behavior inherited from their wolf ancestors.
Attention-Seeking
Dogs often lick their owners in order to get attention or a response. The act of licking usually results in the owner petting or talking to the dog, which reinforces the behavior. Dogs learn that licking elicits a reaction from the owner, so it can become an attention-seeking tactic. According to Rover.com1, “Licking is also your dog’s way of saying, ‘Hey, hello, look at me!’ This attention-seeking behavior is usually reinforced with your positive reaction.” Licking is a way for the dog to get noticed and receive affection or engagement from the owner. If owners want to curb attention-seeking licking, it’s best not to give the dog any reaction after being licked. This will teach the dog that licking does not result in a reward.
1 https://www.rover.com/blog/how-can-i-get-my-dog-to-stop-licking-me/
Anxiety
Licking and nibbling can be a self-soothing behavior for dogs who experience anxiety or stress. Dogs will often lick themselves, people, or objects excessively when they are feeling uneasy or anticipating something stressful like a trip to the vet. This repetitive, soothing motion releases endorphins which help calm the dog. Anxious behaviors like licking may be triggered by loud noises, being home alone, separation from owners, or unfamiliar places and people. If excessive licking seems to occur during times of stress, it likely serves as a coping mechanism for your dog. Some signs your dog’s licking stems from anxiety include increased licking when left alone or around strangers, licking that leads to hair loss or skin damage, and licking that increases during thunderstorms or fireworks. If you notice patterns like these, discuss options with your vet like anxiety medication, a ThunderShirt, or training. Getting to the root of your dog’s stress can help curb anxious licking for comfort. Why Do Dogs Lick – And When to Worry | AKC
Medical Causes
Excessive licking in dogs can sometimes be caused by medical issues like allergies, wounds, or skin irritations. Allergies to foods, pollen, mold, or other environmental factors can cause itchy skin that leads to excessive licking (Source). Licking at hot spots or open wounds can also become excessive as the dog tries to clean and soothe the irritated area. Skin conditions like dermatitis, yeast infections, flea allergy dermatitis, or dry skin can result in itchiness and inflammation that prompts more licking as well (Source). If your dog starts licking excessively, it’s a good idea to take them to the vet for an examination to rule out any underlying medical causes.
How to Reduce Licking
There are several methods you can try to reduce excessive licking behavior in dogs:
Redirect to another behavior – Get your dog’s attention and redirect them to engage in another activity like playing with a toy or chew treat. Giving them an alternative allows them to satisfy their natural inclination in a healthier way. Just be sure the new behavior isn’t also undesirable, like digging or chewing.
Ensure dog gets enough attention/stimulation – Make sure your dog is getting sufficient physical and mental exercise. Take them for longer walks, play more interactive games that challenge their mind, or engage in more petting and quality time together. A tired, fulfilled dog is less likely to default to licking for stimulation.
Rule out medical causes – In some cases excessive licking can indicate an underlying medical issue like allergies, anxiety, intestinal parasites or infection. Check with your vet to diagnose and address any conditions.
For more tips see: Why Your Dog Licks You – And How to Stop It
Conclusion
In summary, there are a few main reasons why dogs lick the back of their owner’s knees. First, it can be a form of affection. Licking releases pleasurable endorphins, and the knees and legs contain familiar scents that comfort the dog. Second, licking can be a sign of submission, showing the dog respects its owner. Third, dogs may lick to groom their owner, much like they lick themselves. Fourth, licking is a way for dogs to seek attention. Finally, anxiety and other medical issues may cause excessive licking behavior.
While licking is normal canine behavior, excessive licking of human body parts like the knees can be bothersome. If it becomes problematic, there are steps owners can take to curtail the behavior, like keeping the dog’s nails trimmed, using bitter sprays, and addressing any underlying medical or behavioral causes.
