The primary function of the mouth is to introduce food into the digestive tract. Additional functions include communication and social interaction, grooming, protection, heat regulation (particularly in dogs), and grasping objects. The latter is very important for performance animals (eg, retrievers, military and police dogs).
Similar to other areas of the alimentary tract, the mouth in the normal, healthy state supports a large and diverse population of bacteria that live primarily in biofilm communities. Unlike other areas of the body, the mouth also contains nonvital surfaces (enamel of teeth) that have neither local immune system defenses nor the ability to regenerate through cellular replacement.
The oral mucosal tissues have an excellent vascular supply, and the tightly adhered gingiva protects the underlying alveolar bone from trauma, thermal injury, and bacterial invasion.
Food prehension requires a complex interaction of the muscles of mastication (masseter, digastricus, temporalis, and medial and lateral pterygoid), teeth, tongue, and pharyngeal muscles. When any of these become compromised through disease or trauma, malnutrition and dehydration can result.
Routine conscious oral examination is an important part of a thorough physical examination in cats and dogs. However, more detailed evaluation of oral and dental health, involving periodontal probing and dental charting as well as dental radiography, can be performed with the patient under anesthesia.
Oral diseases are most effectively treated when diagnosed early. Unfortunately, many problems remain hidden in the mouth until they have progressed to an advanced stage.
For More Information
For a discussion of developmental diseases of the mouth, see Congenital and Inherited Anomalies of the Mouth in Animals.
For a discussion of eosinophilic granulomas, see Eosinophilic Inflammatory Skin Diseases.
Also see pet owner content regarding disorders of the mouth in dogs.