Sublingual Gland
The narrow compact sublingual gland continues forward from the mandibular gland. It follows the mandibular duct between the digastricus ventrally and the medial pterygoid dorsally and soon gains a position lateral to the root of the tongue, before ending variously at the level of the cheek teeth.
Its duct accompanies that of the mandibular gland to the sublingual caruncle; together they raise the sublingual fold, near the body of the mandible. A variable number of lobules of the polystomatic portion of the sublingual gland are present in the sublingual fold, located rostral to the lingual branch of the trigeminal nerve; they open on the floor of the mouth next to the tongue through several ducts. The lingual nerve crosses the lateral surfaces of the mandibular and sublingual ducts just caudal to the level of the orbits.The slitlike openings of the mandibular and sublingual ducts are recognizable on the lateroventral surface of the lingual caruncles, at the end of the frenulum of the tongue (see Fig. 11.14/4). The mandibular duct (Fig. 11.15B), the larger and more rostral of the two, is easily cannulated. The sublingual duct is more difficult to cannulate. In 20% to 40% of dogs the sublingual duct joins the mandibular duct along its course.
The most common clinical condition of the salivary glands in both dogs and cats is the salivary mucocele, which is the accumulation of mucoid saliva leaked from a damaged gland or duct. The sublingual gland is most frequently affected. Extravasated saliva most commonly collects in the subcutaneous tissues of the intermandibular, sublingual tissues (ranula) or cranial cervical area. A less common site is the wall of the pharynx. Treatment requires the removal of the mandibular-sublingual gland complex. Removal of both of these glands does not affect the animal adversely, even if bilateral, but care must be taken to avoid the lingual nerve.
The cat's salivary glands are shown in Figs. 11.6B and 11.27.