Persistent Deciduous Teeth (Baby Teeth) in Dogs

By Lorraine Hiscox DVM FAVD Dip. AVDC; Jan Bellows, DVM, Dipl. AVDC, ABVP

How many sets of teeth do dogs have?

As in humans, dogs have two sets of teeth in their lifetime. Puppies have 28 deciduous teeth also known as primary, baby, or milk teeth. Adult dogs have 42 permanent teeth, also known as secondary teeth.

When do puppies get their deciduous teeth?

Puppies are born without any visible teeth. The deciduous teeth start erupting through the gums around three weeks of age and typically by six weeks of age all the deciduous teeth are present.

A healthy mouth depends on healthy teeth. The ideal time to begin brushing a puppy's teeth begins as soon as you bring your puppy home. The gums are sensitive when teeth are erupting so gentle cleaning during this time is important. Your veterinary health care team can help you determine the best products and methods of dental care for your puppy.

When do puppies get their permanent teeth?

In puppies, the entire teething process is relatively rapid. Teething begins in puppies at about 3½ to 4 months of age, when the deciduous incisors begin to be replaced by permanent incisors. By the age of 6 to 7 months, most puppies have all of their adult teeth.

What happens during teething?

Long before adult teeth erupt through the gums, they begin developing from tooth buds located in the upper and lower jaws. As the adult teeth develop, they begin to exert pressure against the roots of the deciduous teeth, stimulating the roots of the deciduous teeth to begin resorbing. Once the roots have resorbed, the crowns of the deciduous teeth fall out.   You may even find these hollow shells of baby teeth on the floor or in your puppy's bedding, but very often they are swallowed while your puppy is eating to no ill effect.

"Long before adult teeth erupt through the gums, they begin developing from tooth buds located in the upper and lower jaws."

During the teething process, your puppy may drool, may be reluctant to eat as robustly as usual, and may be irritable due to a tender mouth. Almost all puppies have the urge to chew when they are teething. It is important that you do what you can to direct your puppy's chewing towards acceptable and safe objects. Do not allow your puppy to chew people's shoes, clothes, or the furniture. Avoid hard toys, nylon chews, cow hooves, and ice cubes as they can damage the teeth. Avoid feeding your puppy bones (cooked or otherwise), as they are also too hard to chew and can result in damaged teeth and intestinal damage if swallowed.

You may also notice a characteristic breath odor, known as 'puppy breath', which is associated with teething. This odor is normal and will last as long as the puppy is teething.

What is a persistent tooth?

When a deciduous tooth is still present at the time that the permanent tooth has begun to erupt, it is referred to as a persistent tooth. When this happens, the baby tooth occupies the place in the mouth that is meant for the permanent tooth, forcing the permanent tooth to erupt in an abnormal position. The end result is crowding of the teeth and possibly even an abnormal contact of the teeth with either teeth and/or the soft oral tissues. Malpositioned teeth result in an abnormal bite.

Which deciduous teeth are more commonly retained?

The most common persistent teeth are the upper canines, followed by the lower canines and then the incisors. However, any deciduous teeth could be persistent.

Persistent teeth are also more common in small breed dogs, and in brachycephalic breeds (dogs with short noses or flat faces),  such as Bulldogs, Pugs, Boston Terriers, and Boxers.

There may also be a genetic predisposition to developing persistent primary teeth as it often occurs in families of dogs.

What problems are caused by persistent deciduous teeth?

The crowding that results from the persistent tooth and its permanent counterpart will increase the likelihood that food and debris will become trapped between the teeth. An increased tendency to accumulate food debris and plaque can lead to problems such as tartar deposits, gingivitis, and ultimately periodontitis. Additionally, if there is traumatic contact of teeth with other teeth or with the oral soft tissues there will be pain and infection. Teeth contacting other teeth inappropriately can lead to abnormal wear and weakening of the teeth with subsequent tooth (or teeth) fracture.

Occasionally, a persistent deciduous tooth can cause a dental interlock which may interfere with the normal growth and development of the jaws.

If the persistent deciduous tooth is a lower canine, the permanent lower canine is forced to erupt on the inside of the persistent deciduous tooth and as the permanent tooth erupts it will contact the roof of the mouth causing pain and damage which makes it difficult for your dog to eat.

When and how are persistent teeth treated?

As a general rule, no two teeth should be in the same place at the same time. If you notice a persistent deciduous tooth in your puppy's mouth, schedule an appointment as soon as possible with your veterinarian. Typically, persistent deciduous teeth need to be removed (extracted) promptly in order to avoid the secondary problems that occur with the erupting permanent counterpart.

"If you notice a persistent deciduous tooth in your puppy's mouth, schedule an appointment as soon as possible with your veterinarian."

Prompt attention usually allows the adult teeth to move into their proper positions. In most cases, it is not recommended to wait until your pet is neutered or spayed. Extraction of the persistent tooth require general anesthesia. Your veterinarian will take special care during the extraction to avoid damaging the developing roots of the new permanent tooth.

What happens if there is a delay before the retained tooth is extracted?

If the persistent deciduous tooth is not extracted in a timely manner, it is unlikely that the adult teeth will be able to move into their proper positions without orthodontic treatment. In these cases, or for puppies with severe malocclusion problems, it may be necessary to selectively extract other teeth or to refer your dog to a veterinary dental specialist ( for orthodontic treatment to reposition the teeth. This treatment often includes the use of orthodontic devices.

 Is there anything else I should know?

In addition to regular (daily) tooth brushing, it is important to check your puppy's mouth every week until about seven to eight months of age to ensure that his teeth are growing normally. If you find any persistent deciduous teeth, or if you suspect your puppy has an abnormal bite, take him to your veterinary clinic immediately for a thorough oral examination.

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