Do Dogs Have Lips? Let’s Talk About The Rim Of A Dog’s Mouth

As a dog pawrent, you may wonder if your dog has lips like humans. If so, how do dogs use their lips and is there anything special about them?

A dog’s lips may not be as luscious as a human’s, and they definitely don’t need lipbalm, but they’re there. In fact, they’re an essential part of a dog’s oral structure, which needs to be kept clean with mouthwashes for dogs and good dental care. Come to think of it, wouldn’t it be weirder if dogs didn’t have lips? It certainly would make dogs look far scarier.

So let’s take a closer look at dog lips, what their function is, and what we need to know about them to help our dogs.

Dog Lip Anatomy

Looking closely at your pup’s mouth, you’ll see their head, floppy ears, sharp teeth, and muzzle, but you may not see the lips. That’s because you need to look a little closer since a dog’s lips are not as obvious as ours.

The upper lips are called flews, and they appear to have a partition right below the nose. They are made of fat and fibroblastic tissues; some people call them jowls. However, jowl is really a broader term referring to the thick skin on dogs’ cheeks and throats.

View this post on Instagram

A post shared by Corey Jo Compton (@cjstraightoutta)

The larger the flews, the more the drool. Dog breeds like Bulldogs, Bassets, Bloodhounds, Bull Mastiffs, and Saint Bernards, just to name a few, have massive droopy flews So, as you can expect, these are some of the most notorious droolers because these heavy lips pull down the corners of their mouth, leaving the edges open for saliva to drip out.

Unlike humans, dog lips are made of strong tissues. These consist of:

• An outer integument layer;
• A middle muscular;
• A fibro elastic layer; and
• An inner mucosal layer. Therefore, a dog’s lower lip is like a thick fold of skin surrounding the mouth.

The upper and lower lips converge at an angle located near the first cheek tooth. A dog’s lips are self-contained with tissue, glands, vessels, and nerves between the inner and outer lining. Facial nerves provide the sensory function to the lip muscles, while the cranial nerve provides motor function. These nerves thus allow your pup to move their lips and feel pain. Lips are an essential part of a dog’s anatomy that we don’t think much of, much like their Adam’s apple. 

View this post on Instagram

A post shared by @bellamyandfinnwoof

Why do dogs need lips?

The primary role of lips in dogs is to hold a bone firmly when chewing or a toy when playing. Lips are also vital for thermoregulation. Lips in dogs are just as essential as lips in humans for everyday function. That’s why every dog has lips, even those with heavy jowls.

Lip Functions in Dogs Include:

• Allowing dogs to hold food in their mouth.
• Lips are essential to control body temperature. Open lips allow cool air into the mouth when a dog is panting, while closed lips trap warm air in the mouth. This makes dogs with heavy flews more prone to heatstroke.
• Picking up scents, especially pheromones left by other dogs. Dogs improve their smell when they curl their upper lips, which flares their nostrils, allowing them to smell better. Lips also play a role in allowing air into the mouth to gather scent particles.
• Lips protect the mouth and gums from dirt and other foreign objects.
• Additionally, dogs use lips to communicate their feelings, either anger or fear, when they lick them or when they lift their lips in a snarl. Dogs also lick their lips when they feel sick or nauseous.
• Help to retain saliva in the mouth.

Let’s not forget that another key reason dogs have lips is to hide their pills in their jowls and spit them out when you aren’t looking!

Why Do Dogs Have Serrated Lips?

The ridges on a dog’s lips are called “ruga” or “rugal folds” and are an important part of their lip anatomy. Their main function is gripping onto food as your dog chews so that it does not slip out and to move the food to the back of the mouth. Other ruga functions include the following:

1. The serrations provide a bit of extra grip on food a dog is chewing on.
2. The serration on a dog’s lips protects their gum from the sharp canines. Dogs’ upper jaw and lower jaw canine teeth rest on the serrated lip protecting the gum from the sharp canines. They may act as sensors that keep the lip out of the teeth’s way, preventing the dog from biting their own lip.
3. The serrations may also help absorb shock whenever your dog bites something with force, like when playing frisbee or fetch.
4. Research also suggests serrated lips in dogs help increase their grip when carrying objects from one point to another.
5. They could also act as a toothbrush as they naturally brush your dog’s teeth, keeping them clean. However, they can be a site for bacterial accumulation, so check on these areas frequently.
6. The ruga create suction when a dog drinks water or eats semi-solid food, which moves it down the mouth toward the throat, making them part of how dogs swallow.
   

Common Dog Lip Problems

Numerous health conditions can affect your dog’ lips. Here we are going to shine the light on some of them. Your pooch’s mouth is prone to harmful and destructive bacteria if ignored.

This is observed mostly in brachycephalic (short-nosed) dogs and dogs with saggy skin on their face. Due to their short skull with wrinkles and saggy flews they are likely to trap food particles, acting as homes for bacteria in their the corners of the mouth. An example is the saggy open end on this Bullmastiff’s mouth:

Mouth problems in dogs can occur gradually, so we don’t always notice them in time.

Common problems in dog lips include:

Lip Wounds

Dog fights Dogs fancy dominance and will do anything to sit on the throne. Fighting can result in wounds all over, including the lip. Chewing hard and sharp objects like sticks and plastics also wounds their mouth and lips.

When dogs lick their wounds to ease the discomfort, they can transfer more microbes to their lips. The licking can cause secondary bacterial infections.

Lip Fold Dermatitis

This is inflammation in the lip folds around a dog’s face. The folding becomes a hiding place for bacteria to thrive due to a lack of air circulation, warmth, and moisture trapped in the fold.

When the bacteria lingers for a long time, it slowly weakens the skin’s outer surface, penetrating the epidermis and getting into your puppy’s system, and causing more skin problems. The disease is mostly observed in dogs with heavy flews and jowls and brachycephalic dogs like Bulldogs, Saint Bernards, Neapolitan Mastiffs, and Shar Peis.

Dogs suffering from lip dermatitis may have a stench coming from their mouth even when you’ve been taking care of their teeth. The infected area may appear red, slightly warm, and painful.

The most effective method to prevent lip fold dermatitis is occasionally cleaning and drying around the inflamed wrinkles. Cleaning will prevent bacteria from building up and clean any trapped particles in the folded area.

Oral Papillomas

This condition is where a non-cancerous benign grows from your pup’s lips, gum, and mouth. It is also known as warts, caused by Carnivore boca parvovirus 1 or CPV-1. Pooches under two years are more prone to this disease because their immune system hasn’t fully developed.

Warts often disappear suddenly or can be removed through surgery. However, applying imiquimod has also proven to boost your dog’s immune system making it strong to handle the virus. Warts can be undetected, especially if your pup has saggy lips.

Dog lip cancer (melanomas)

Not all dogs have black lips, and white dogs (or light-colored dogs) may have pink lips that is vulnerable to damage from the sun, and can cause cancer in the lips. For dogs who do not have black lips, it’s essential to put a thin layer of doggy sunscreen on the area before they go outside.

However, oral melanomas do not only affect dogs with pink lips. Some breeds prone to oral melanoma include: 

• Dachshunds;
• Cocker Spaniels;
• Chows;
• Golden Retrievers;
• Miniature Golden Retrievers;
• Poodles; and
• Scottish Terriers.

Discoloration

Most dogs have black lips. However, color in the lips can change due to a number of reasons. In most cases, the black lip starts getting pink patches.

Various reasons could lead to lip discoloration in your pup’s lips.

Some medical conditions causing discoloration in a dog’s lips include:

• Lupus;
• Injuries;
• Pyoderma;
• Vitiligo;
• Excessive drooling;
• Uveodermatologic syndrome; and
• Allergies.

Some of these diseases could deteriorate if left untreated and lead to worse conditions. The fur around a dog’s mouth may also gradually become reddish brown. This is staining due to a substance called porphyrin in dog saliva and tears. You should only notice the red or brownish color around a dog’s mouth in light colored dogs. To prevent this staining, we suggest drying the mouth area regularly with dog wipes and following the same procedure to clean tear stains on your dog.

Chapped Lips

Dogs’ lips get dry, too, although very rarely. Dry lips can be caused by allergies, dehydration, vitamin deficiency, playing with toys made of fiber, and dermatitis. If you have been asking why dogs lick the air, chapped lips might be the reason.

Frequently Asked Questions (FAQs)

Final Thoughts    

Dogs have lips though they are not visible as humans. Their lips act as a grip, hold firm a bone when chewing, help them to control their body temperature, contain what is in the doggo’s mouth, and protect the jaw. It’s advisable to frequently wash your dog’s mouth using a dog mouth rinse. Cleaning helps avoid bacteria that seek refuge in your dog’s mouth or saggy lips.  

Meet Your Experts

Tamsin De La Harpe

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.

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.