Persistent Deciduous Teeth (Baby Teeth) in Cats

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

How many sets of teeth do cats have?

As in humans, cats have two sets of teeth. As kittens they have 26 deciduous teeth, also known as primary, baby, or milk teeth.  As adult cats they have 30 permanent teeth.

When do kittens get their deciduous teeth?

Kittens are born without any visible teeth. The deciduous teeth start erupting through the gums at around three weeks of age and are normally finished erupting by 6 to 8 weeks of age.

A healthy mouth depends on healthy teeth. The ideal time to begin brushing a kitten’s teeth is when you first bring them home before the discomfort of teething begins. During the brief period when the baby teeth are falling out and the permanent teeth are erupting, it is recommended that you take a break from brushing. Your veterinary health care team can help you determine the best products and methods of dental care for your kitten.


When do kittens get their permanent teeth?

In kittens, the entire teething process is relatively rapid. Teething begins in kittens at about 10 weeks to 6 months of age, beginning with the primary incisors being replaced by their permanent counterparts. By the time the average kitten reaches 6-7 months of age, all 30 adult teeth will have erupted.

What happens during teething?

Buried in the bone of the jaws, beneath the baby teeth, adult teeth, known as tooth buds, are forming. As the adult teeth develop, they begin to move through the bone and erupt through the gums. Ideally, the baby tooth associated with that permanent tooth falls out. You may even find these hollow shells of the baby teeth on the floor or in your kitten’s bedding, but more often than not the teeth will fall out while the kitten is eating and they will swallow them with the rest of their food.

The teething process can be a time of discomfort and your kitten may drool, be reluctant to eat at times, and may be irritable due to a tender mouth. Almost all kittens will have the urge to chew when they are teething. It is important that you do what you can to direct your kitten’s chewing towards acceptable objects. Avoid giving your kitten hard objects that could damage their teeth.

"The teething process can be a time of discomfort and your kitten may drool, be reluctant to eat at times, and may be irritable due to a tender mouth."

You may also notice a characteristic breath odor (kitten breath), which is associated with teething. This odor is normal and will last as long as the kitten is teething.

Sometimes however, the permanent tooth erupts alongside the baby tooth. When the baby tooth is still present at the time that a permanent tooth has begun to erupt, it is referred to as a persistent deciduous tooth.

What is a persistent tooth?

A persistent tooth occurs when the tooth root of a deciduous tooth is either incompletely resorbed or it did not resorb at all and as a result, does not fall out. 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 at an abnormal angle or in an abnormal position. The end result is often crowding or malposition of the tooth, causing an abnormal bite (malocclusion).

Which deciduous teeth are more likely to be persistent?

The most common teeth to be persistent are the upper canine teeth, followed by the lower canine teeth, and then the incisors. However, in some cases, the premolar teeth may also be retained.

What problems are caused by persistent teeth?

If both a deciduous tooth and a permanent tooth are in the same socket in the jaw, the crowding of the two teeth will increase the likelihood that food and debris will become trapped between the teeth. This can lead to problems such as tartar deposits, tooth decay, gingivitis, and periodontitis - all of which can lead to premature loss of teeth. If the root of the retained tooth has only been partly resorbed, it can become badly infected.

If teeth are malpositioned, they can rub against other teeth, wearing away the enamel and weakening the tooth. Occasionally, a persistent deciduous tooth can cause a dental interlock which may interfere with the normal growth and development of the jaw bones.

If the persistent tooth is a lower canine, the permanent lower canine is forced to grow on the inside of the lower jaw 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 cat’s ability to eat comfortably.

When and how are persistent teeth treated?

No two teeth should be in the same socket at the same time. If you notice a persistent tooth in your kitten's mouth, make an appointment with your veterinarian as soon as possible to schedule an examination. Unless the baby tooth is very mobile, extraction is the treatment of choice. It is not recommended to wait until your kitten is neutered or spayed.

"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. Extraction of the retained tooth will require a general anesthesia along with intraoral radiographs (X-rays) before and after the extraction. Your veterinarian will take special care during the extraction of any persistent tooth to avoid damaging the immature roots of the new permanent tooth.

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

If the persistent primary 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 kittens with severe malocclusion problems, it may be necessary to selectively extract other teeth or to refer your cat to a veterinary dental specialist ( for orthodontic treatment to reposition the teeth. This treatment often includes the use of orthodontic appliances such as buttons and elastics. See handout "Orthodontics (Moving Teeth) in Cats for more information.

Is there anything else I should know?

In addition to regular tooth brushing, it is important to check your kitten's mouth every week until about seven to eight months of age to ensure that her teeth are growing normally and in the appropriate position. If you notice any persistent teeth, or if you suspect your kitten has an abnormal bite (malocclusion), take her to your family veterinarian immediately for an oral examination.

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