Veterinary Q & A - Salivary Gland Cyst (Sialocele)

My vet just diagnosed the lump under my dog's jaw as a sialocele - what is that, exactly?
A salivary gland cyst is also known as a sialocele or salivary mucocele. There are four salivary glands in the dog and cat. The most commonly affected glands are the large ones under the jaw, the mandibular salivary glands. The sublingual (under the tongue) can also be affected.

A sialocele is a cyst filled with a collection of mucoid saliva in the tissues surrounding a salivary gland. These cysts can become quite large, sometimes inducing a cough (from pressing on the larynx or trachea).

Oh no - how did this happen?
The exact cause is often hard to determine, but causes include trauma to the gland or ducts, infection, or possibly a growth that obstructs the ducts, causing rupture. The saliva and mucus then escape into the surrounding tissues.

Are salivary gland cysts a painful condition?
These cysts can be painful when they first occur, but most animals are presented with a large, non-painful, fluctuant mass under the jaw or under the tongue. These cysts CAN become infected, causing pain and generalized fever. Also, the large size of some masses, while not always painful, can sometimes functionally interfere with breathing or eating.

My vet did a needle aspirate - is that a sure-fire way to diagnose this condition?
Needle aspiration -- taking a small needle, inserting it into the lump, and aspirating cells or liquids is a very useful diagnostic tool for many situations, including salivary cyst. The characteristic aspirate is a clear, sticky or stringy fluid (saliva) that may be tinged with a little blood. It is important to look at the sample microscopically too, to rule out other diseases, such as cancer or infection. It will also help differentiate between a salivary gland and other tissue, for example, a swollen lymph node (also in the area).

My vet recommended surgery - is this necessary?
Surgical removal of the damaged gland and duct is the treatment of choice. Some cases can be managed by installing drains and periodic emptying of the cyst. Some cysts will resolve on their own, but infection, pain, and critical obstruction of the airways are potential risks if treatment is not utilized. Since there are four different salivary glands in different locations, please discuss what would be the best individual treatment option for your pet.

Do you know anybody else who has faced this decision?
Click here to read a viewer-submitted Success Story about a successful salivary gland surgery

Viewer Viewpoint: hear from a vet who uses echography to diagnose this condition.

Don't Miss: Related Reading (from the Diseases & Conditions section of this site):

Salivary Mucocele
See surgical treatment photos of this condition. Sialadenectomy = removal of the gland. Marsupialization = suturing the duct opening to the area under the tongue for continued drainage.

Salivary Sialocele (Mucocele)
A Question and Answer format about this condition and treatment, from VetCentric.

Salivary Sialocele in a dog
Histopathology photos from a needle aspirate.

Salivary Sialocele Slide Show
From the Louisiana State University School of Veterinary Medicine.

Parotid Salivary Sialocele in a Cat
Short abstract from the Feline Practice, 1998, Vol 26, Iss 4, pp 6-8.

Thanks for stopping by!

¹Merck Veterinary Manual, 8th edition, pg 702

Text: Copyright © Janet Tobiassen Crosby. All rights reserved.