A dog’s lips might not need lip balm, but they’re a vital part of your pup’s anatomy. Think about it: wouldn’t it be weirder if dogs didn’t have lips? Those lips play a key role in eating, drinking, communicating, and even staying cool. Let’s take a closer look at what dog lips are, how they work, and what makes them unique.
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What Are Dog Lips Called
Dog lips are made up of upper lips, called flews, and lower lips, which form a thick fold of skin around the mouth. These lips are more muscular and fibrous than human lips and are made of multiple tissue layers that include nerves, glands, and vessels.
The flews (especially in breeds like Bulldogs or Bloodhounds that are known for their jowls) hang down from the sides of the upper jaw, often causing excess drool. These heavy lips also play a role in regulating heat and catching scent particles.
But the areas we may think of as the lips is really where the outer protective skin transitions to the mucosal lining on the inside of their cheeks and mouth. This is called the vermillion zone.
According to Dr. Diana Eubanks, DVM: “The lips are comprised of three components, one of which is the facial stratified squamous epithelium portion. The vestibular component is covered with oral mucosa that is non‐keratinized to parakeratinized squamous epithelium. The juncture where the lips meet the surrounding skin is the vermilion border, and the pigmented area within the borders is called the vermilion zone.”
Translation? The outer part of the lip is tough skin. Inside, it transitions to a softer, moist area more like the inside of the mouth. That border between the two? That’s the vermilion zone, and it’s part of why some dogs have dark lips that can look like they have lip liner.
Want to watch your dog’s adorable lip-licking moments while you’re out? Check out the Petcube Cam 360.
Why Do Dogs Have Black Lips
Not all dogs have black lips, but most do. That dark pigment usually comes from melanin, the same thing that gives color to human skin and hair. Even white-haired dogs, like the Maltese, usually have black lips and eyelids, since this melanin protects this sensitive skin from UV-rays and cancer.
However, not all dogs have this. Many dogs have pinker skin and may have light pink lips or patches of pink and black.
As a user on Reddit writes: “Not all dogs have black ‘lips.’ If they do, it’s because their skin is dark under their hair. They have less hair around their mouth, and it gets even darker since it's exposed to the sun and cold.”
So, if a dog has dark skin, they should have black lips. But light-colored dogs with light skin may well be born with pink lips and that’s normal. However, the lips can also turn pink or lighter for a number of reasons, including infections, trauma, or autoimmune issues.
Although more often, it’s just a normal pigment change that could happen much like “snow nose”, which is when a dog’s nose turns pink in winter. It’s possible the lips could lose some pigment over winter or with age too.
Why Do Dogs Have Ridges on Their Lips
Ever noticed those little ridges or serrated edges on your dog’s lips? They’re not just decoration. They’re called rugae (or “rugal folds”), and they’re there for functional reasons:
- Rugae help the lips grip food and toys, keeping them from slipping.
- They act as a cushion between the gums and sharp canine teeth.
- They help soften the impact or absorb shock when your dog chomps down hard (like on a frisbee).
- The ridges rub against teeth and help clean as your dog chews, but they also trap bacteria, so don’t forget to clean your dog’s teeth.
- Rugae also help draw water or semi-solids into the throat when drinking or eating. They effectively help seal the mouth like a vacuum, creating a little less mess.
Remember, pet hydration is easier when water is flowing and clean, so check out the Petcube Fountain to keep those lips happy and healthy.
Why Do Dogs Need Lips
Dog lips do more than keep the drool in check. Here’s why they’re essential:
- Holding food and managing water intake without sloshing everywhere.
- Opening the lips allows cool air to flow during panting. Closing them helps trap heat in when they’re cold. So lips help with controlling body temperature (thermoregulation). This is also why dogs with heavy jowls (flews) overheat more easily.
- Dogs curl their lips to enhance airflow into their nostrils and into their mouths, so their lips help them gather scent particles to enhance their sense of smell.
- Lips shield the gums and teeth from dirt, debris, and impact, so they act as protection.
- Lifting lips to snarl, licking when nervous or pulling back the lips in fear, are just some of the many ways dogs use lips to communicate.
- Lips help keep the mouth from drying out during rest or play, by trapping the saliva in the mouth (mostly; not always the case for super droolers).
And finally, don’t forget that many dogs know how to hide pills in their cheeks or lip folds to avoid taking them. Some dogs have mastered this use of their lips, so always check their mouth after giving any oral medication to make sure they actually swallowed it.
Conclusion
Dog lips are more than just cute. They’re built to protect the mouth, communicate feelings, and even control body temperature. So, they’re a pretty vital part of dog anatomy.