Structure and Function of Dog Tongue, Teeth, and Mouth

A dog’s mouth — including the tongue and teeth — plays a crucial role in eating, drinking, grooming, and even regulating body temperature. Together, these structures form the oral cavity, which is the entry point to the gastrointestinal tract. Understanding how the tongue, teeth, and mouth are built and how they function can help dog owners better recognize signs of disease and know when veterinary care is needed.

Anatomy and Location of the Tongue

The tongue is a long, flexible, muscular organ located on the floor of the mouth. It attaches at the back of the throat to a small bone called the basihyoid and extends forward to the tip of the dog jaw.

Covered in tiny projections called papillae — many of which contain taste buds — the tongue helps dogs taste and move food, chew, and swallow. It is also full of blood vessels, which means it can bleed heavily if injured. Salivary glands open around the tongue and release saliva into the mouth to moisten food and aid digestion.

Anatomy and Types of Teeth

A dog’s teeth are highly specialized and designed for grasping, tearing, shearing, and grinding food. Dogs normally develop 28 deciduous (baby) teeth, which later fall out and are replaced by 42 permanent teeth.

These include incisors at the front of the mouth for nipping, sharp canine teeth used for gripping and tearing, premolars located just behind the canines for slicing and grinding, and molars at the back of the mouth for the heaviest chewing. Each tooth has a visible crown above the gum line and one or more roots anchored into the jawbone below the gums.

Teeth are made of several layers, including the soft inner pulp that contains nerves and blood vessels, a middle layer of dentin, and a hard outer layer of enamel on the crown. The roots are covered with cementum and held in place by the periodontal ligament.

Structure of the Mouth and Oral Cavity

The mouth itself forms the space between the upper and lower jaws and is lined with a moist mucous membrane. The roof of the mouth is divided into the hard palate in the front and the softer, flexible soft palate toward the back. The lips help retain food inside the mouth while the cheeks and tongue move food during chewing.

Numerous salivary glands empty into the mouth, contributing saliva to help lubricate and digest food. The mouth also serves as an airway during heavy breathing or panting, especially when dogs are exercising or when nasal airflow is restricted.

How the Dog Tongue, Teeth, and Mouth Function Together

The tongue, teeth, and mouth work together to process food and maintain overall health. The tongue guides food and water into the throat, assists with swallowing, and plays a key role in tasting. Dogs also use their tongues for grooming, cleaning wounds, and — especially in puppies — stimulating urination and defecation. During panting, air flows over the tongue, and evaporating saliva helps cool the body.

The teeth break food into smaller pieces, and each type of tooth fulfills a different role in chewing. Meanwhile, the salivary glands in the mouth produce saliva, which lubricates food, begins digestion, forms it into a swallowable mass (bolus), and helps keep the mouth clean.

Common Diseases of the Tongue, Teeth, and Mouth

Like any part of the body, the mouth and tongue can develop disease. Disorders of the tongue may cause drooling, bad breath, bleeding, pain, or reluctance to eat. Dental disease is extremely common in dogs and may involve the teeth, gums, or supporting structures. Signs include foul breath, difficulty chewing, discoloration, bleeding, and visible deformities.

Retained baby teeth — especially in small breeds — may remain beyond six months of age and cause crowding or bite problems. Malocclusion, or misalignment of the bite, may also develop and can lead to abnormal tooth wear or gum trauma.

One of the most common problems in dogs is periodontal disease, which begins with plaque buildup on the teeth. Over time, plaque hardens into tartar, leading to gum inflammation (gingivitis), infection, and eventually destruction of the tissues supporting the teeth.

Dogs may also develop tooth root abscesses, especially in the premolars and molars. These infections may cause swelling — sometimes beneath the eye — and can even drain through the skin. Tooth fractures, worn teeth, and abrasions from chewing hard objects are also common and may expose the sensitive pulp, resulting in pain.

Tumors may form on or near the teeth and gums. Some, such as epulides, are benign but can grow large enough to cover teeth, while others are more aggressive and require surgical treatment. The mouth itself may also be affected by conditions such as stomatitis, salivary gland disorders, and tumors. Ranulas — cysts that develop beneath the tongue due to blocked salivary glands — may cause swelling and interfere with eating or tongue movement.

Diagnostic Tests Used to Evaluate the Mouth

To diagnose problems affecting the tongue, teeth, or mouth, veterinarians begin with a thorough oral examination, often using sedation or anesthesia to allow complete inspection. A full physical exam helps determine whether other organs are affected. Additional tests may include swabs for cytology and culture, bloodwork to evaluate infection or systemic disease, dental X-rays to assess tooth roots and jaw structures, and biopsies of abnormal tissue. In some cases, surgical exploration is needed to confirm a diagnosis and begin treatment.

The Importance of Oral Health in Dogs

Because the mouth plays such an essential role in a dog’s daily life, maintaining oral health is a key part of overall veterinary care. Recognizing early signs of dental or oral disease — such as bad breath, drooling, bleeding, difficulty chewing, or changes in behavior — can help ensure your dog receives timely treatment and stays comfortable and healthy.