Dog Drooling and Salivary Gland Problems

The dog has four pairs of salivary glands that drain into the mouth. Only the parotid gland, located below the dog's ear on the side of the face, can be examined from the outside. The salivary glands secrete an alkaline fluid that lubricates the food and aids in digestion.

Hypersalivation (Drooling)

Some degree of drooling is normal in dogs, particularly in breeds with loose, pendulous lips. Excessive drooling is called hypersalivation. Hypersalivation is commonly triggered by psychological events such as fear, apprehension, and nervous anxiety, as well as anticipation of food treats.

Drooling also occurs in response to mouth pain caused by periodontal disease, abscessed teeth, and stomatitis. A dog who drools excessively and acts irrationally should be suspected of having rabies. Distemper, pseudorabies, and heat stroke are other diseases associated with drooling. Another common cause of drooling is motion sickness.

Tranquilizers cause drooling, as do many poisons. When a dog drools for no apparent reason and appears healthy, look for a foreign body in the mouth.

Treatment:This depends on the cause of the drooling.

Salivary Gland Cysts, Infections, and Tumors

The salivary glands can be injured as a result of fights and lacerations of the head and neck. The damaged duct or gland may leak saliva into the surrounding tissue, forming a fluid-filled cyst called a mucocele. This occurs most often in the mandibular glands, located in the floor of the mouth. Mucoceles in this location are known as a honey cysts or ranulas. A ranula presents as a large, smooth, rounded swelling in the floor of the mouth on the right or left side of the tongue.

Mucoceles cause problems when they become large enough to interfere with eating or swallowing. If a needle is inserted into the swelling, a thick, mucuslike, honey-colored material is extracted. This may eliminate the problem, but more often surgery is required. It involves draining the cyst into the mouth. If this is not successful, the salivary gland can be removed.

Salivary gland infection is uncommon. Most cases are associated with preexisting mouth infections. The zygomatic gland, located beneath the cheek bone, is the gland most often involved. The signs of zygomatic gland infection are a bulging eye, tearing, and pain on opening the mouth. Treatment involves removing the gland.

Tumors of the salivary glands are rare. Most are malignant. They appear as slowly enlarging lumps or masses located beneath the tongue or on the side of the face. Small tumors can be cured with surgical removal.

This article is excerpted from “Dog Owner’s Home Veterinary Handbook” with permission from Wiley Publishing, Inc.