Like humans, dogs and cats have baby teeth, called deciduous teeth, that are replaced by permanent teeth as the puppy and kitten grow and develop. The deciduous teeth begin to erupt around 2 to 3 weeks of age while the permanent adult teeth erupt between 3 to 7 months in dogs and 3 to 6 months in cats. When puppies and kittens lose their baby teeth, you might notice blood on their gum, lip, or tongue. This is normal. You may or may not find little teeth scattered around on the carpet or floors. If your pet swallows them, they will not cause any problems.
There are four types of teeth found in mammals:
Incisors – incisors sit at the front of the mouth and help the animal cut and grasp food
Canines – canines sit behind the incisors and are used to stab and tear food
Premolars – premolars sit behind the canines and are used to grind food
Molars – molars sit at the back of the mouth and are used to grind food
A tooth is divided into two parts – the crown and the root. The crown is the visible part of the tooth outside of the gum, while the root lies within the gumline and anchors the tooth in the mouth.
Normally, as the permanent tooth begins to develop, it will push against the root of the deciduous tooth. The body will then break down the deciduous tooth root until it can no longer be anchored in the mouth and eventually falls out. In some cases, however, the deciduous teeth remain in the mouth even as the permanent teeth come in. This is called persistent deciduous teeth and requires the surgical removal of the remaining deciduous teeth (see photo below).
While extraction of persistent deciduous teeth can be tricky due to their long roots, it is important to remove the retained teeth as soon you or your veterinarian notices them as they can cause the permanent teeth to become misaligned or displaced in the mouth, leading to future dental problems and an increased risk for periodontal disease. The teeth typically affected are incisors and canines and are usually seen in small, toy breed dogs. The dental x-ray above shows a Maltese with retained incisors and canine teeth. The photo of the extracted teeth below shows the roots that did not dissolve. The third photo shows the puppy’s perfect smile after removal of the retained deciduous teeth.
Periodontal disease (gum disease) is one of the most common diseases found in dogs. More than 80 percent of dogs show early stages of the disease by the time they are 3 years old. Periodontal disease is caused by plaque bacteria, and the immune system’s destructive reaction to it. Without regular cleaning, dental plaque accumulates and becomes mineralized, forming dental calculus or tartar. Once it has mineralized, dental calculus becomes much more difficult to remove.
Periodontal disease ultimately causes damage to teeth and their underlying supportive structures (i.e., gingiva, bone, ligaments). Early detection and treatment are critical because advanced periodontal disease can cause pain, loss of teeth, and even jaw fractures.
Periodontal disease can also impact systemic health. It can make dogs more likely to develop diseases of other organs, including the heart, lungs, kidneys, and liver, and it can make other disease processes like diabetes more difficult to control.
The most common dental disease in domestic cats is a destructive process called tooth resorption. This painful condition is believed to affect more than 65% of cats during their lifetime. The cause of tooth resorption is currently unknown, but the condition seems to develop when a cell within the tooth called an odontoclast is activated and removes calcium from within the tooth structure. The tooth then starts to erode, often from within. As the disease progresses, the pulp cavity becomes exposed, causing sensitivity and pain.