The salivary glands in mammals are exocrine glands, glands with ducts, that produce saliva. They also secrete amylase, an enzyme that breaks down starch into maltose. There are four major silavary glands including the mandibular, sublingual, parotid, and zygomatic gland. Adenocarcinoma of salivary glands can affect any of these glands but most commonly affected gland is mandibular gland.
This tumor arises in the salivary gland and is usually malignant in nature. It spreads quickly throughout the body. Though the tumor is generally locally invasive and regional lymph node metastasis is common; it has the potential to metastasize and affect other distant parts of the body. Older dogs are most commonly affected by this tumor.
The symptoms depend on which salivary gland is affected. Common symptoms include
Painless swelling of upper neck, ear base, or upper lip
Halitosis (foul breath)
Dysphagia (difficulty in swallowing)
Exophthalmos (bulging of eye)