This is one of the most interesting and unclear questions concerning dogs and comes with many theories. While coming from dog experts, most of these theories do not hold much proof. So there’s not a lot of reliability here, and we have to use our common sense when accepting these theories.
So, why do dogs have serrated lips? There are a lot of theories and explanations on why dogs have serrated lips. According to experts, dogs have serrated lips for a number of natural reasons. Some theories say that serrated lips help dogs grip things better, clean their teeth and increase food taste. Other reasons include the protection of their lips, acting as a cooling mechanism, and much more.
As you can see, there’s not just one but many reasons for this phenomenon. There’s still plenty of research being done on this topic, so we don’t really have the whole truth here. However, we can go through a list of theories and ascertain how true they are.
Why Do Dogs Have Serrated Lips – The Theories

The list of theories is long and keeps increasing with every new discovery. So let’s take a look at these theories and some more and try to figure out this puzzle for ourselves.
The Better Grip Theory
Experts suggest that one of the reasons dogs have serrated lips is to grip onto things tightly. This seems like a plausible explanation because dogs use their mouths to grab onto things. Let us experiment to understand this concept better and figure out how accurate it is.
We humans find it impossible to grab onto anything considerable using our mouths. It’s no problem if we’re biting onto a small object like a pencil; we can achieve that without failing miserably. However, should we try to bite onto a baton and carry it somewhere, we’ll find that it’s not so easy. If our teeth don’t give up within minutes, we’ll start feeling a painful sensation on our lips and jaws.
The human mouth is not designed for carrying things; that’s what we use our hands for. On the other hand, dogs do not have opposable thumbs, so they cannot use their paws to grab anything. This is why they have to resort to using their teeth and lips. Because of this, experts believe that dogs have maintained serrated lips in their evolution process. The lip serrations, combined with sharp and strong teeth, allow dogs to carry big objects using their mouths effortlessly.
Another sub-theory is that the lip serrations help maintain a balance in the force used while gripping. You see, when dogs grab onto objects like balls or bones, they don’t have to control the force applied. Even if they bite hard, they aren’t going to damage the ball or bone. However, we all know that dogs also carry their pups using their mouths and teeth. So, does that mean the dog bites hard onto the pup to latch onto it?
Experts say lip serrations ensure that the pups don’t get hurt as mommy doggo grabs them. However, many reject this theory claiming that dogs naturally know how much pressure to apply. Either way, there is no sustainable proof to support these theories, so go figure.
The Teeth Cleaning Theory
Frederick Wood Jones, a professor of anatomy, introduced the concept that serrated lips help keep a dog’s teeth clean. To explain, let’s take the example of humans yet again. As we know, we humans clean our teeth by brushing them with a toothbrush.
Similarly, dogs clean their teeth by brushing them against grass or similar plants. In fact, modern teeth cleaning toys for dogs include soft spikes that brush against a dog’s teeth while they chew.
To conclude, Frederick Wood Jones believes that the serrations on the lips naturally brush against a dog’s teeth. This can be a natural and biological way for dogs to keep their teeth clean from the inside.
The Taste Increase Theory
Some people believe that serrations increase the amount of skin inside the mouth, giving dogs the ability to taste more. However, this theory has been strongly debunked and is not a reliable concept.
The theory comes from knowing that dogs don’t have too many taste buds on their tongues. Yet, we witness dogs gorging on meals every day with a permanently strong appetite. So, people started figuring that perhaps a dog’s taste buds are not limited to its tongue, but spread throughout the mouth. If this was true, that would mean that the lip serrations carry some of the taste buds.
This theory does not hold enough weight because dogs use their smell to make up for the lack of taste buds. So the idea that lip serrations carry taste buds is idiotic at best.
The Lip Protection Theory
This theory comes from the observation that dogs have sharp and strong teeth that overlap when their mouths are closed. With such sharp and pointy teeth, it’s surprising that dogs never cut their lips while chewing. Imagine if humans had sharp teeth like that, we’d be cutting our lips every single moment.
This leads people to believe that lip serrations protect a dog’s lips while chewing or biting. The theory is not difficult to believe as the serrations have a rubbery feel which keeps the teeth at bay. Moreover, when a dog has its mouth closed, the teeth rest on the serration. So it literally provides an extra layer of coating that prevents any cuts or gashes.
As we all know, cuts and injuries on a dog’s lips can easily get infected with bacteria and cause diseases. So it makes sense that the evolution process would provide some kind of natural protection against this.

The Cooling Mechanism Theory
If you live in a hot and humid place, chances are you’ve seen your dog panting profusely to cool themselves off. This is done by evaporating moisture from the dog’s mouth and nose, decreasing body heat. Some people believe that lip serrations add to the effect of losing moisture.
The theory that lip serrations add more area for moisture evaporations seems logical. However, there is little to no evidence that actually proves this theory.
The Puppy Tool Theory
A minor theory regarding lip serrations claims that they are necessary for pups to latch onto their mother while feeding. We would like to term this theory ‘the puppy tool’. A newborn pup doesn’t have sharp or strong teeth nor a lot of strength to bite onto things. Yet, they can grab onto their mother effortlessly while feeding. How is that possible?
Well, that’s where the serrated lips come in. Many believe that the primary function of these serrations is so that pups can hold onto their mother without biting. It could be that the serrations provide a coating that sticks onto the mother’s udders as they feed. Of course, there is no scientific proof for this, so we’ll have to rely on our own eyes.
Possibility of Harmful Lip Serrations?
We aren’t sure why dogs have serrated bumps on their lips yet. With all the existing theories, we must believe the theory that makes the most sense. However, we know that serrated bumps on dogs’ lips are good for them. Thanks to these serrated bumps, dogs have several advantages that we’ve already discussed.
However, serrated bumps aren’t the only bumps your dog might have on its lips. Dogs might have other kinds of harmful bumps on their lips, which is why it’s important to know how to take care of a dog. Serrated bumps are usual, but anything apart from these can be something harmful.
If you see unknown large bumps on your dog’s lips or tongue, it might be a tumor that could result in cancer. So how to take care of your dog in this situation? We recommend taking your dog to the vet immediately. Regular visits to the vet are a key factor in ensuring good health and long life for your dog.
Another harmful possibility is that your dog might have canine acne, leading to harmful results. Most people are unaware of this possibility and don’t know how to check it. Luckily for you, we can guide you on how to take care of a dog. All you have to do is simply check your dog’s lips for red bumps or pimples. If you find any of these spots, we recommend immediately taking your doggo to the vet.

Conclusion on Why Do Dogs Have Serrated Lips
Despite having so many theories, there is no absolute answer to why dogs have serrated lips. There are many more theories invented by experts and dog owners alike; however, we didn’t find them worth mentioning. In our opinion, we find only two of the six listed theories to carry some sense.
One is the theory that lip serrations help dogs to grab onto things. Other than the serrations, no other element suggests the ability to clinch onto things. So, therefore, it does seem likely that lip serrations help dogs achieve this feat.
The second theory is the puppy tool concept, which is essentially a prologue to the ‘grabbing’ concept. If pups used the serrations to latch onto their mother’s body, it makes sense that the same serrations are used to grab onto other objects when they grow up. This leads us to believe that only these two theories are reliable, but then again, others could think otherwise. So when it comes to answering the question of lip serrations, you have to think for yourself!
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