How Dog Teeth Develop and What Can Go Wrong

Jul 30 • 10 min read

You find a tiny white tooth on the living room floor and panic for a second did your puppy break a tooth? Or your vet glances in your adult dog's mouth during a routine visit and casually mentions his canine tooth is "tilted" and might need attention. Dog teeth go through a surprisingly complex developmental process, and knowing the basic timeline tells you exactly what's normal and what needs a vet's eye.

Dogs grow two full sets of teeth in their lifetime 28 deciduous ("baby") teeth that begin erupting at 3 to 5 weeks of age, and 42 permanent teeth that start coming in around 4 to 5 months and are fully in place by about 7 months. Development happens in three distinct stages, and each stage has its own specific set of things that can go wrong from bite problems and retained baby teeth to enamel damage and, eventually, gum disease.

Key Takeaways

Dogs have 28 baby teeth and 42 permanent teeth permanent teeth erupt from roughly 4 to 5 months and are all in by 7 months of age.
Vets can estimate a young dog's age fairly accurately from tooth eruption timing, which matters a lot in India, where street dog and shelter adoptions often come with no birth records.
Dental development happens in three stages (0–16 weeks, 16 weeks–7 months, 7 months–1.5 years), and each stage has its own characteristic problems overbite/underbite issues, retained baby teeth, and tooth crowding respectively.
Small and brachycephalic (flat-faced) breeds face a disproportionate share of dental problems unerupted teeth, crowding, and rotated teeth are all more common in these dogs.
Gum disease is the single biggest cause of tooth loss in dogs, and it has two distinct stages reversible gingivitis and irreversible periodontitis which is exactly why catching it early matters.
A home dental care routine, even a modest one, genuinely changes outcomes: dogs on hard kibble and regular brushing develop meaningfully fewer dental problems than those without either.

The Two Sets of Teeth Every Dog Grows

Diagram comparing a dog's deciduous baby teeth to permanent adult teeth with eruption timelines.

Every dog, just like every human, grows two full sets of teeth over a lifetime. The first set deciduous, or "baby," teeth numbers 28 and begins erupting at 3 to 5 weeks of age. These are eventually replaced by 42 permanent teeth, which usually start appearing around 4 to 5 months of age and are all present by roughly 7 months.

Each tooth type is shaped for a specific job a meat-eating animal like a dog has very different teeth from a grass-eating animal like a horse and the exact sequence in which teeth erupt and get replaced follows a fairly predictable timeline across breeds, even though small and toy breeds sometimes deviate from it.

Using Teeth to Estimate a Dog's Age

Because tooth eruption follows such a predictable timeline in young dogs, vets can use it to estimate age reasonably well in puppies mostly based on which teeth have erupted and when. In adult dogs, the picture shifts to wear patterns on the teeth, which give experienced vets a workable age estimate, though this is genuinely more accurate in large breeds than in small or toy breeds.

This matters more in India than in most places, precisely because of how common it is to adopt a dog whether a street dog, a shelter rescue, or a puppy from an unofficial litter with absolutely no birth record. A dental exam is often the very first real clue to a rescued dog's actual age, and it directly shapes decisions around vaccination timing, spay/neuter scheduling, and general health expectations going forward.

The Three Stages of Dental Development — and What Goes Wrong at Each

Timeline infographic of the three stages of dog dental development and common problems at each stage.

Proper development of a dog's mouth and teeth depends on a series of events happening in the right sequence and when that sequence gets disrupted, longterm complications follow. Vets divide dental development into three stages, each with its own characteristic problems.

Stage	Age Range	What's Happening	Common Problems
Stage 1	0–16 weeks	Baby teeth erupt; jaw growth begins	Overbite/underbite from baby teeth blocking jaw growth; extra teeth; uneven left-right jaw growth
Stage 2	16 weeks–7 months	Baby teeth shed; permanent teeth erupt	Retained baby teeth; tilted canine teeth; overbite becoming apparent
Stage 3	7 months–1.5 years	Full adult bite settles in	Tooth crowding; rotated teeth (especially in brachycephalic breeds)

Stage 1 is where jaw-length problems get their start. Puppies are actually born with a slight overbite a longer upper jaw which helps them nurse. As a puppy moves to solid food, the lower jaw goes through its own growth spurt. If certain lower baby teeth erupt before that growth spurt happens, they can get caught behind the upper teeth and physically block the lower jaw from reaching its proper length meaning the "quick fix" here is sometimes simply extracting a few baby teeth to free up the jaw's growth path. The reverse can also happen: an overly fast-growing lower jaw produces an underbite, detectable as early as 8 weeks, treated the same way but with upper baby teeth removed instead.

Stage 2 is dominated by one issue above all: retained baby teeth. Normal shedding starts around 14 weeks with the upper central incisors, and over the following three months, baby teeth are steadily replaced. If a baby tooth doesn't fall out when its permanent replacement is already coming in, the two can crowd each other and push the permanent tooth into an abnormal position a problem that's simple to prevent if the retained tooth is spotted and removed promptly, but harder to fix once the adult tooth has already settled crooked. Tilted canine teeth are another Stage 2 issue, seen disproportionately in Shetland Sheepdogs though reported across many small breeds, and orthodontic correction (genuine "braces" for dogs) is sometimes used depending on severity and age.

Stage 3 brings crowding and rotation issues to the forefront, especially in flat-faced, brachycephalic breeds a category that includes some of India's most popular current companion breeds, like Pugs, Shih Tzus, and French Bulldogs. Their comparatively short jaws simply don't have enough room for a normal-sized set of teeth, so crowding and rotation are almost structural rather than incidental. Treatment, when needed, ranges from orthodontic correction to straightforward extraction of the most problematic teeth.

Unerupted Teeth: The Hidden Risk for Small Breeds

Some breeds small breeds like Maltese in particular are prone to teeth that simply never erupt through the gumline. Brachycephalic breeds face a related but distinct version of the same problem: their teeth fail to erupt because they're sitting in an incorrect position to begin with, a direct consequence of the same crowded jaw anatomy discussed above.

This isn't purely cosmetic. An unerupted tooth can form a cyst that, left unchecked, destroys a significant section of the jawbone. This is exactly why vets recommend x-rays of any area where a tooth appears to be missing, repeated periodically rather than checked just once an unerupted tooth needs monitoring, not a single all-clear. Any dog with unerupted teeth should also be spayed or neutered, since the tendency runs in families.

Enamel Defects: When Illness or Malnutrition Leaves a Mark

Tooth enamel forms during a specific developmental window, and anything that disrupts that window fever, malnutrition, certain chemicals can leave a permanent mark on the tooth. Canine distemper virus deserves particular mention here, because it does double damage: it directly attacks the cells that produce enamel, and it causes fever, both of which weaken the resulting enamel. A dog that survived distemper as a puppy can carry visibly thinner, weaker enamel for life as a lasting sign of that illness.

This is a genuinely relevant point in India, where distemper still circulates among unvaccinated street dogs and, occasionally, reaches under-vaccinated pet dogs through contact with them. Severe malnutrition in young dogs can produce a similar enamel-weakening effect independent of any specific disease. Isolated enamel defects on a single tooth, by contrast, usually trace back to localised trauma or infection in that specific tooth rather than a body-wide cause.

From Gingivitis to Periodontitis: How Gum Disease Progresses

Infographic comparing reversible gingivitis to irreversible periodontitis in dogs.

Gum (periodontal) disease is the single biggest cause of tooth loss in dogs, and it develops in two distinct stages that matter enormously for treatment and outlook.

Gingivitis is the reversible first stage bacterial plaque accumulates at the gumline, gums turn from healthy coral-pink to red or purple, swell, and bleed easily on contact, and bad breath sets in. Crucially, at this stage the ligaments and bone holding the tooth in place are still intact, which is exactly why thorough professional cleaning under anaesthesia can fully reverse it. Left untreated, though, gingivitis progresses.

Periodontitis is the irreversible second stage, where the damage extends to the ligaments and bone themselves, causing permanent loss of the tooth's support structure. A few patterns are worth knowing: small-breed dogs develop periodontitis more often than large-breed dogs; back teeth are affected more than front teeth; upper teeth more severely than lower teeth; and dogs fed a regular diet of hard kibble develop fewer problems, thanks to the simple mechanical scraping effect of chewing. Gingivitis is often first noticed around 2 years of age, while periodontitis typically sets in between 4 and 6 years if the earlier stage was never addressed. Treatment at this stage usually requires professional cleaning above and below the gumline, x-rays to assess bone loss, and in many cases extraction, which dogs tolerate remarkably well once the underlying infection and pain are resolved.

Trauma, Fractures, and Tooth Decay

Teeth can fracture from external trauma aggressive play, a road accident or from biting something too hard: real bones, hooves, antlers, hard nylon toys, rocks, or cage bars. Signs include a painful reaction to touch, a reddish-brown, purple, or grey discolouration, a visible fracture, or facial swelling though most dogs mask dental pain remarkably well, which is precisely why a fracture can go unnoticed for a long time without a specific vet check. Treatment is either extraction or a root canal, decided based on whether the fracture reaches the tooth's inner pulp.

Tooth decay (cavities) is genuinely uncommon in dogs, unlike in humans, and when it does occur it typically shows up as pits on the chewing surfaces of the molars. When cavities do happen, they're filled using techniques similar to human dentistry.

The India Factor: Street Dogs, Diet, and Home Dental Care

A few pieces of this picture line up specifically with Indian pet-parenting realities. Adopted street dogs and shelter rescues arrive with genuinely unknown ages, and a dental exam is frequently the most useful tool a vet has for estimating it worth mentioning explicitly if you've recently adopted, since it shapes decisions on vaccination catch-up schedules and neutering timing. Distemper exposure, discussed above, remains a real risk in India's large unvaccinated street dog population, and enamel damage in a rescued adult dog can be a lingering sign of a distemper infection survived as a puppy.

On the diet side, the traditional Indian habit of feeding dogs primarily soft home food rice, roti, dal rather than hard kibble removes exactly the mechanical scraping action that helps keep plaque in check day to day. This doesn't mean home-cooked food is inherently bad for teeth in isolation, but it does mean dogs on predominantly soft diets benefit more, not less, from an active brushing routine or dental chews to compensate for what chewing kibble would otherwise be doing.

Building a Home Dental Care Routine

The single most important fact about gum disease is straightforward: it will not develop around clean teeth. Daily toothbrushing is genuinely the gold standard, but wiping teeth with gauze every 2 to 3 days is a workable fallback for dogs that won't tolerate a brush. Only the outer surfaces of the teeth actually need cleaning you don't need to fight your dog to get at the inside surfaces. Never use human toothpaste; it's formulated to be spat out, and dogs swallow whatever goes in their mouth. Dental chews, textured toys, and diet can all support the routine, but none of them fully substitute for direct brushing or wiping when it's genuinely needed.

When to See a Vet

Book a dental check if you notice any of the following:

Bad breath that's noticeably worse than usual
Red, swollen, or bleeding gums
A tooth that looks discoloured, chipped, or fractured
Reluctance to chew, dropping food, or chewing only on one side
A retained baby tooth still present alongside an erupting adult tooth
Any facial swelling, especially near the jawline
A puppy or newly adopted dog whose age is unknown a dental check can help estimate it accurately

None of these need to wait for the next annual check-up. Dental problems tend to compound quietly over months, and catching gum disease at the gingivitis stage while it's still fully reversible makes a real difference to your dog's long-term comfort and tooth retention.

FAQ Section

How many teeth do dogs have, and when do they come in?
Dogs have 28 deciduous (baby) teeth, which begin erupting at 3 to 5 weeks of age, followed by 42 permanent teeth that start coming in around 4 to 5 months and are fully in place by about 7 months.

Can a vet tell a dog's age just by looking at its teeth?
Yes, reasonably well in young dogs, based on tooth eruption timing. In adult dogs, vets look at wear patterns instead, which works better in large breeds than in small or toy breeds, where age estimation from teeth is genuinely harder.

What's the difference between gingivitis and periodontitis?
Gingivitis is the early, reversible stage of gum disease inflamed, bleeding gums with the ligament and bone still intact and it responds well to professional cleaning. Periodontitis is the later, irreversible stage, where the supporting ligaments and bone are permanently damaged, often leading to tooth loss if untreated.

Why do small and flat-faced breeds have more dental problems?
Their jaws are proportionally smaller, so there's often not enough room for a normal-sized set of teeth. This leads to more crowding, tooth rotation, unerupted teeth, and in the case of periodontitis specifically a documented higher rate of gum disease compared to large breeds.

Does feeding home-cooked food cause more dental problems than kibble?
Not directly, but soft food doesn't provide the mechanical scraping action that chewing hard kibble does, which naturally helps control plaque. Dogs on predominantly soft, home-cooked diets benefit more from an active brushing or dental-chew routine to make up the difference.