Oral and Dental Anatomy of Dogs & Cats (Common Conditions)

Treatment options

Carnassial abscesses are typically seen in older dogs, especially those over seven years of age. By the time we are able to actually recognize a problem, the initially affected root is often dead. Veterinarians today can save the tooth with a procedure similar to the 'root canal.' This can be fairly expensive, but it does save the tooth. Therapy is followed by a long-term use of antibiotics to prevent future problems.

Salivary glands

Dogs and cats have four pairs of salivary glands. Each gland has its own duct that carries saliva from the gland to the mouth cavity. Saliva keeps the inside of the mouth lubricated, makes the swallowing of food easier, and contains enzymes that can help begin the digestion of food. In animals that pant, saliva also aids in cooling animals through evaporation off of the tongue.

Numbers of teeth

Many mammals, including dogs and cats have two sets of teeth, one baby teeth set (called "deciduous") being shed and replaced by an adult or permanent set. Although the exact number can vary, puppies have 28 deciduous (temporary) teeth, and adult dogs have 42 permanent teeth. Feline kittens have 26 deciduous teeth, and adult cats have 30 permanent teeth.

What are the risks?

Retained baby teeth frequently cause a crowding of the teeth along the gumline. This crowding displaces the permanent teeth so that they are out of line or grow at odd angles. The abnormal placement of teeth can interfere with the normal growth and development of bones in the jaws. They may contact the roof of the mouth causing injury and pain. Retained teeth may also die and abscess, causing mouth infections to develop.

What is the management?

Retained deciduous teeth should be extracted. This will usually require anesthesia and surgical extraction. Check a puppy's mouth weekly until about seven months of age for abnormal teeth

Tooth Eruptions

Teething in the puppy refers to the process of growing baby teeth (deciduous teeth) and ends with the adult or permanent teeth. The first baby teeth, sometimes referred to as 'milk teeth,' erupt from the gumline around four weeks of age. These teeth are small and very sharp. They may scratch the nipples, resulting in discomfort to the nursing mother. By about six weeks of age, the baby teeth are sufficiently painful to the mother's nipples to cause her to begin to wean the puppies from the nursing process. The first deciduous teeth to come in are the canine teeth and incisors, followed by the premolars and molars. Puppies generally start to lose the deciduous teeth at age 2-3 months of age. As with the deciduous teeth, the incisors are the first permanent teeth to erupt. They are followed by the canines, molars, and premolars. Most puppies are undergoing some form of continued teething, either erupting or replacing the baby teeth, until they are about nine months of age. The exact end to teething varies considerably with each individual puppy. Teething puppies love to chew. This may be an attempt to relieve the irritation associated with raw and occasionally bleeding gums.

Signs and development of a carnassial tooth abscess

An infection of the 4th premolar is a unique dental problem and has outward signs that are often misunderstood by the owner. The large carnassial tooth has three roots, while most other teeth have only 1 or 2. From 1/2" to 3/4" long, they extend from below the gumline up into the bone of the skull just in front of the eye. There are two in the front portion of the tooth and one in the rear. Carnassial tooth infections actually involve only the roots of the tooth and not the visible exposed portion. The individual root usually involved is the front one that is closest to the skin. Carnassial tooth infections are caused by bacteria that gain access to the root, either by working their way under the gum at the base of the tooth or by being carried there by the bloodstream. Once the bacteria are in this location between the root and the bone of the skull, the body has a very difficult time ridding itself of the infection. Treatment may control the outward signs but when the medication is discontinued, the infection returns. The bacteria take up residence on the surface of the root and slowly destroy its attachment to the jaw. In doing so, they deprive the root, and therefore, the tooth, of its blood supply. This eventually leads to death of the affected tissue. Dead tissue in the body is treated the same way as a splinter or other foreign material. In an attempt to isolate and repel the material, the body shunts millions of WBCs into the area to: • Isolate it from the remaining healthy tissue. • Dissolve or break it down so that it can be eliminated as typical cellular waste. • Expel it whole from the body. This accumulation of white blood cells at the site of an infection or necrotic material is referred to as pus or an abscess. In the case of a carnassial tooth, the abscess builds up around the affected root just under the skin below and in front of the eye. The swelling may reach the size of a golf ball. In the case of an abscess, the white blood cells and chemicals that are released have the ability to dissolve the body's tissue. The weakest portion of the body in this case is the skin, so a small hole soon opens from which pus (or a pink-tinged fluid) will drain. Left alone, this opening will occasionally close but then reopen later as more material accumulates. Owners often confuse this condition with an eye infection, insect bite, or puncture wound. They may consider it something that, if left alone, will heal on its own. The untreated abscess will, in fact, often spread to 1) the eye causing a very serious and potentially blinding infection or 2) other teeth causing them to be lost also. This is fairly painful for the animal, especially when eating. In dogs that stay outdoors or those with long hair, it may remain unnoticed for a long period of time.

Tooth anatomy

Each tooth has a crown (located above the gums) and a root (located below the gums). Some teeth, such as incisors, have one root, while others, such as the largest cutting premolar, called the "carnassial tooth," has as many as three roots. A tooth is composed of the following structures: Pulp: The pulp is at the center, or core of the tooth, and consists of connective tissue, nerves, and blood vessels that nourish the tooth. Most of the nerves and blood vessels to the tooth enter through the apex (bottom) of the root. Dentin: The majority of the tooth is made up of dentin, which surrounds the pulp. Dentin is as hard as bone but softer than enamel. Dentin is a tissue that can detect touch, heat, and cold. Primary dentin is dentin that is formed before tooth eruption; secondary dentin is dentin that is continually formed throughout the life of the tooth. Enamel: Enamel is the hardest tissue in the mammalian body and is formed before tooth eruption. Just before the tooth erupts through the gums, the formation of enamel stops and is lost gradually over the life of the tooth. Although enamel is very hard, it is brittle, too, often subject to chipping. Alveolar bone: The alveolar bone forms the jaw and the sockets into which the roots of the teeth extend. Cementum: Cementum is hard, calcified tissue that covers the dentin of the root and is slowly formed throughout the life of the tooth. It assists in supporting the tooth in the jaw and in root repair. Gingiva: The gingiva, also called the "gums," is the soft tissue that covers the rest of the peridontium.

What are the signs?

In puppies with a retained deciduous tooth, a permanent tooth is seen along side the baby tooth it was meant to replace. The permanent canine teeth usually erupt in front of the deciduous canines.

Infections of the 4th Premolar (Carnassial Tooth

If you look inside a dog's mouth you will notice one tooth that is much larger than the rest. It is on the upper jaw, about half way back. It is the fourth premolar, sometimes referred to as the carnassial tooth. In wild canines, it is the main tooth used to break up or crush hard material in their diet such as bones or large pieces of meat. Today's canine diets, even the all-dry ones, really do not require this big "work horse" tooth for the animal to adequately break up his food before swallowing. Still, it is there, and it poses some unique problems for the older dog.

Tooth eruption

In kittens and puppies, the deciduous teeth begin to erupt at about 3-4 weeks of age and the permanent teeth begin to emerge at about 3-4 months of age. By 24 weeks of age, usually all of the permanent teeth have emerged.

Tongue and gums

The tongue is a very complex organ. It is made up of a system of muscles enabling the intake of food into the mouth and manipulating it to allow the animal to chew and swallow. Even among carnivores, the tongue functions differently. For example, when dogs drink water, the water is transported from under the tongue into the mouth. When cats drink, the water is transported from the top of the tongue. This difference is especially noticeable in sound: a drinking cat is relatively silent while a dog has to gulp more as he manipulates his tongue in the water and in his mouth. Hiccups in dogs, especially puppies, are common as dogs tend to swallow more air when drinking. The tongue is usually pink in color. Dogs may have an occasional dark blue-black marking, while certain breeds, such as the chow, have a totally blue-black tongue. The tongue is covered with taste buds that distinguish flavors. The tongue is also used as a grooming tool. The feline tongue is covered in backwards-facing, barb-like structures called "papillae" that wash, smooth, and dry the coat; they also aid in the removal of meat from bones.The gums are most often pink in color but can vary among species. In the dog, like the tongue, the gums, as well as the inner cheeks, can have patches (or solid pigmentation) of dark blue to black

Retained Deciduous (Baby) Teeth

Usually by four weeks of age puppies get their deciduous teeth, commonly known as baby teeth. Beginning around three months of age, the deciduous teeth are replaced by the bigger and stronger permanent teeth. It takes an additional three to five months for the permanent teeth to replace all of the baby teeth. Occasionally, the permanent teeth do not erupt immediately under the deciduous teeth, and therefore, do not force the baby teeth out. When a dog has both an adult and baby tooth at the same site, it is referred to as a retained deciduous tooth. In the dog, this usually occurs with the incisors or upper canine baby teeth.