Why Do Dogs Teethe? | The Grumpy Phase Most Owners Miss

Your puppy is gnawing the furniture, drooling on every surface, and nipping at your toes with tiny, needle-sharp teeth. It’s easy to assume this is just naughty behavior, but there’s a biological reason behind the chaos. That mouthful of baby teeth is making way for a permanent adult set.

Dogs teethe because they are diphyodont — they grow two sets of teeth in their lifetime. The 28 deciduous (baby) teeth begin falling out around 3 to 4 months of age, pushed out by the 42 permanent adult teeth. This process can cause sore gums, increased drooling, and a powerful urge to chew on anything available.

What Exactly Happens During Puppy Teething

Teething occurs because the roots of the deciduous teeth are reabsorbed by the body, causing them to loosen and fall out as the permanent teeth push up from below. It is very similar to teething in human babies — the same fussiness, the same desire to chew, and the same gum discomfort.

Puppies have 28 baby teeth, which are already in place by about 6 to 8 weeks. The permanent teeth start erupting around 3 to 4 months. By 6 months, all 42 adult teeth should have come through, assuming no issues like retained deciduous teeth.

The Role of Each Tooth Type

A dog’s 42 adult teeth include incisors for nibbling and scraping meat off bone, canines (the four pointed fangs) for holding and tearing, and premolars and molars for chewing and grinding. Each plays a specific role in eating and playing.

Why The Intense Chewing and Nipping Happens

When a puppy teethes, the driving force behind most of its behavior is pain relief. Chewing helps ease irritated gums and relieve the pressure of teeth pushing through. This is not just bad behavior — it is a biological need that requires safe outlets.

• Relieving gum pressure: Chewing massages the gums and helps the baby teeth loosen, making the process less painful for the puppy.
• Exploring the world: Puppies use their mouths the way human babies use their hands. During teething, the mouth is extra sensitive and interesting to them.
• Nipping is normal: Nipping at fingers and toes is a standard teething behavior. While annoying, it can be managed with training and redirection rather than punishment.
• Irritability and drooling: Just like a teething infant, a puppy can become fussy. Increased drooling, red or inflamed gums, and a general grumpy mood are common signs of teething.
• Bleeding gums: In more extreme cases, teething can cause slight bleeding at the gum line. A little blood where a tooth fell out is normal, but heavy bleeding warrants a vet visit.

Rotating available puppy-safe toys helps keep a teething puppy interested in appropriate chewing. If they are bored with their toys, the baseboards or your sneakers become fair game.

When a “Teeth Display” Isn’t Aggression

During the teething months, you might catch your puppy displaying their tiny pearly whites in a way that looks threatening. Most people assume a dog showing its teeth is a sign of aggression, but during puppyhood it can mean something much gentler.

Some dogs learn a submissive “smile” as a sign of respect or greeting. Per WebMD’s guide to dog smiling teeth, a relaxed body and wagging tail usually accompany this greeting, distinguishing it from genuine aggression.

If the puppy is stiff, growling, or guarding a toy, that is real aggression. Teething can make puppies possessive of items they want to chew, which is another behavior to manage with training. Understanding the difference helps you respond correctly.

How to Help Your Teething Puppy Safely

Managing a teething puppy is about channeling their chewing drive onto safe items while protecting your home. The goal is not to stop them from chewing, but to guide them toward the right things.

1. Offer cold relief: Chewing cold or frozen items, such as a frozen washcloth or puppy-safe teething toys, can help relieve teething pain. The cold numbs the gums and reduces swelling, similar to a teething ring for a baby.
2. Choose toys wisely: Avoid giving teething puppies very hard toys or bones that you cannot indent with your fingernail, as these can cause broken teeth. Offer a mix of rubber toys and soft toys instead.
3. Rotate the selection: Rotating available puppy-safe toys helps keep a teething puppy interested and engaged in appropriate chewing. A new toy every few days feels like a treasure.
4. Redirect, don’t punish: When your puppy chews a forbidden item, calmly redirect them to a toy. Punishment for teething behavior can create anxiety and worsen the nipping.

The Big Picture — Permanent Teeth Are Here to Stay

Unlike sharks, dogs cannot regrow lost or damaged teeth. If an adult tooth is lost, it is gone permanently, just as in humans. This is why protecting those new 42 teeth is so important once teething is complete.

How do puppy teeth fall out? The roots of the deciduous teeth are reabsorbed, causing them to loosen — PetMD covers this process in its article on how puppy teeth fall out.

The entire teething process typically wraps up by six months of age. Once the permanent teeth are in, the heavy chewing should subside (though many dogs remain enthusiastic chewers for life). At this point, maintaining dental health with brushing and vet check-ups becomes the new priority.

The Bottom Line

Dogs teethe to replace their 28 baby teeth with 42 permanent adult teeth, a process that typically runs from 3 to 6 months of age. The heavy chewing, drooling, and occasional nipping are normal responses to gum pain, not bad behavior that requires harsh discipline.

If your puppy seems unusually uncomfortable, has severe bleeding, or you find a retained baby tooth alongside an adult tooth, your veterinarian can help. They can check for dental issues like retained deciduous teeth (which may need extraction) and recommend safe pain relief options specific to your puppy’s age and breed.