Persistent Deciduous Teeth (Baby Teeth) in Dogs

By Tammy Hunter, DVM; 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. 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 are normally finished erupting by 6 weeks of age.

A healthy mouth depends on healthy teeth. The ideal time to begin brushing a puppy's teeth is as soon as you bring them 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?

The teething process is relatively rapid in puppies. Teething begins in puppies at about 3.5 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 them 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 often they are swallowed while your puppy is eating, to no ill effect.

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 toward acceptable and safe objects. Do not allow your puppy to chew the furniture, or people's shoes or clothes. 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?

A dog's persistent deciduous teeth have caused a tooth fracture due to abnormal contact of the teeth.A deciduous tooth that is still present when the permanent tooth erupts 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 result is crowding of the teeth and possibly even abnormal contact of the teeth with either teeth and/or the soft oral tissues. Malpositioned teeth result in an abnormal bite (malocclusion).

Which deciduous teeth are more commonly persistent?

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 - all of which can lead to premature loss of teeth.

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 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 tooth is a lower canine, the permanent lower canine is forced to grow on the inside of the persistent tooth and its tip usually grows towards the roof of the mouth. Contact of the canine teeth with the roof of the mouth may result in significant trauma, pain, and may interfere with your dog’s ability to eat comfortably.

When and how are persistent teeth treated?

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

"Early extraction in these cases will usually allow the adult teeth to move into their proper positions and prevent further malocclusion problems."

Early extraction in these cases will usually allow the adult teeth to move into their proper positions and prevent further malocclusion problems. In most cases, it is not recommended to wait until your pet is neutered or spayed. Extraction of the persistent tooth requires 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 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 refer your dog to a veterinary dental specialist (avdc.org) for orthodontic treatment to reposition the teeth. This treatment often includes the use of orthodontic devices. See handout "Orthodontics (Moving Teeth) in Dogs” for more information.

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 the teeth are growing normally. If you notice any persistent deciduous teeth, or if you suspect your puppy has an abnormal bite, take them to your veterinary clinic immediately for a thorough oral examination.

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