Two rows of teeth in a puppy almost always means retained deciduous teeth: a baby tooth that failed to fall out while its adult replacement erupted alongside it. The upper canines are the most common offenders, and small and toy breeds account for a large share of cases. This is not something to wait out. A retained baby tooth crowds the adult tooth, traps food and plaque in the gap between them, and can push the permanent tooth into a position that causes trauma every time the mouth closes. The usual answer is extraction, and the usual timing is sooner rather than later.
The most common explanations
- Retained deciduous teeth. The permanent tooth erupted beside the baby tooth instead of underneath it, so the root of the baby tooth was never resorbed and the tooth stayed put. This is the answer in the large majority of cases.
- Normal overlap during eruption. For a brief window, a loose baby tooth and an emerging adult tooth can both be visible. If the baby tooth is wobbly and the overlap is days rather than weeks, this may resolve on its own.
- Supernumerary teeth. Genuinely extra permanent teeth, more common in some breeds. These need assessment rather than assumption.
- Delayed or abnormal eruption. Occasionally a permanent tooth erupts at an unusual angle or in an unusual position, which changes what the mouth looks like without a retained tooth being involved.
The timeline that tells you whether to worry
Puppy dentition follows a fairly predictable schedule, which makes it easy to judge whether your puppy is on track.
The rule veterinary dentists work from is simple: two teeth of the same type should never occupy the same space at the same time. A day or two of overlap while a baby tooth loosens is normal. Weeks of two firmly seated teeth is not.
Why waiting causes damage
There are three separate problems, and they compound.
Crowding and plaque. The gap between a retained baby tooth and its adult neighbor is a narrow, sheltered space that traps hair, food, and plaque. It is nearly impossible to clean, and periodontal disease begins there far earlier than it would otherwise. In small breeds whose mouths are already crowded, this accelerates a problem that would have arrived eventually anyway.
Displacement of the permanent tooth. The retained tooth occupies the position the adult tooth was meant to take. The adult canine, in particular, gets pushed forward or inward, and it may not seat correctly for the rest of the dog's life. The longer the baby tooth stays, the more established that position becomes.
Traumatic occlusion. A lower canine pushed inward can strike the roof of the mouth every time the jaw closes. This causes ulceration and pain, and correcting it later is far more involved than removing a baby tooth would have been.
That last point is why "let's see if it falls out" is a costly plan. Extraction of a retained deciduous tooth is a routine procedure. Correcting a malpositioned adult canine is orthodontic work.
Which puppies are most affected
Toy and small breeds carry the highest risk. A Yorkshire Terrier, a Pomeranian, a Maltese cross, a Chihuahua, or any dog whose jaw has to accommodate the same forty two adult teeth in a much smaller frame is more likely to have a deciduous tooth fail to resorb.
If you have a small breed puppy, put a reminder in your calendar to check the mouth weekly from about sixteen weeks. Lift the lip, look at the canines specifically, and count. It takes fifteen seconds and it catches the problem in the window where it is easy to solve.
Many veterinarians will plan to remove retained teeth at the same time as a spay or neuter, since the puppy is already under anesthesia. Raise it early enough that this option is still on the table.
Caring for a puppy mouth that is changing
Teething is uncomfortable, and a puppy in that phase will chew whatever is available. Give them appropriate outlets and keep the hard objects away, since a puppy tooth or a newly erupted adult tooth can fracture on a bone or an antler just as an adult tooth can.
Start handling the mouth now, before there is any reason to. Lift the lip daily, touch the gums, make it unremarkable. A puppy who accepts face handling becomes a dog you can actually brush, and that single habit shapes the next decade of dental health.
Introduce dental chews sized for a young mouth rather than an adult one, and supervise every session. Ark Naturals Soft Brushless offers a softer format that suits puppies past teething and dogs with tender mouths, and you can see how it compares with the firmer formats in the Ark Naturals collection. Check with your veterinarian about the right age to begin, since a mouth mid eruption has different needs than a settled one. Whatever you use works on soft plaque above the gum line and sits alongside, not in place of, the professional care your veterinarian recommends.
For a broader picture of what puppy dental development should look like, the AAHA pet dental care resource is a good general reference.
When this needs a veterinarian
Book an appointment within the next week or two if your puppy is over sixteen weeks and has a baby canine sitting alongside an erupted adult canine, if any baby tooth has been present alongside its replacement for more than a couple of weeks, or if your puppy is approaching seven months with any deciduous tooth still in place.
Seek care the same day for a puppy who has stopped eating, has significant bleeding from the mouth, has a swollen face, or is crying while chewing.
Raise it promptly, rather than waiting for the next scheduled visit, if you can see a lower canine striking the roof of the mouth, if there is an ulcer or a red indentation in the palate, or if the bite looks visibly wrong when the mouth closes. Those situations get harder to fix with every week that passes.
Frequently asked questions
Will a retained baby tooth fall out on its own eventually?
Sometimes, but relying on it is a gamble with a poor payoff. The root did not resorb, which is the whole reason the tooth stayed. Meanwhile crowding, plaque accumulation, and displacement of the adult tooth continue.
Is extraction of a retained puppy tooth a big procedure?
It is a routine one, performed under anesthesia, often at the same time as a spay or neuter. The roots of deciduous canines are long and fragile, so it is done carefully and with radiographs to confirm nothing is left behind.
Which breeds get this most?
Toy and small breeds are heavily overrepresented, including Pomeranians, Yorkshire Terriers, Maltese, Chihuahuas, and the small poodle crosses. Larger breeds can have retained teeth, but it is less frequent.
My puppy has two rows of incisors. Is that as urgent as canines?
Retained incisors matter less for bite alignment but still trap plaque and crowd the mouth. They should be assessed, and they are usually removed if they persist past the normal shedding window.
Can I help the loose tooth come out?
No. Do not pull or wiggle it. Deciduous roots are long and break easily, and a retained fragment causes ongoing infection. Let your veterinarian handle removal.