A sialocele is a condition of the salivary glands or ducts. The condition appears as swollen structures in the neck near the jaw, under the tongue, or by the eye. It is a buildup of saliva that can often resemble a cyst and it is usually treated by surgery in dogs.
What is a Sialocele?
A sialocele is an accumulation of saliva that develops in the tissues near a salivary gland or duct due to leakage. Sialoceles are sometimes called salivary mucoceles or salivary cysts. Though not technically cysts, the fluid buildup causes a swollen structure that resembles a cyst. They are soft, fluid-filled, and generally painless. Sialoceles are relatively rare in dogs, but they are the most common type of salivary problem seen in dogs.
Symptoms of Sialoceles in Dogs
Sialoceles can affect various glands or associated ducts. Here are the four types of sialoceles:
Sialoceles do not cause pain in the early stages unless they become large enough to put pressure on another part of the anatomy. Symptoms exhibited will depend on the type of sialocele.
Swelling of the Neck/Jaw (Cervical)
The most common type of sialocele is a cervical one which occurs under the upper neck or jaw and originates from the sublingual or mandibular gland or duct. Swelling may occur in the middle of the neck/jaw or off to one side.
Swelling Under the Tongue (Sublingual)
Another common sialocele occurs in the mouth under the tongue and comes from the submandibular gland or duct. The sialocele may be in the center or on one side and can displace the tongue if large enough. This particular type of sialocele is called a sublingual or ranula.
Swelling Near the Eye (Zygomatic)
In rare cases, a sialocele develops from the small zygomatic salivary glands located beneath the eye. Facial swelling may appear near the eye and it may cause the eye to bulge.
Trouble Eating, Swallowing, or Breathing (Pharyngeal)
Less commonly, a pharyngeal sialocele develops in the pharynx at the back of the throat. This is similar to a cervical sialocele as it stems from the mandibular or submandibular glands or ducts. Pharyngeal sialoceles can disrupt swallowing and breathing.
Causes of Sialoceles
The exact cause of sialoceles is not known, but they are likely caused by traumatic injuries to the tissues of the salivary glands and ducts. Here are the three likely causes:
- Oral injury from chewing on an object
- Bite wounds from another animal
- Choke collar injury from pulling
Diagnosing Sialoceles in Dogs
After discussing your pet's history, your veterinarian will perform a physical examination and look closely at the swollen area. Here are the two phases of diagnosis:
- Aspiration: Your vet may want to aspirate the area with a needle and syringe to collect the fluid for testing. Your dog may need sedation for this depending on the location.
- Lab Analysis: The fluid from a sialocele is generally clear, yellowish, or blood-tinged in color and slightly viscous like saliva. Your vet may be able to see right away that it is saliva, but will likely send the fluid to a lab for analysis to be certain. A veterinary pathologist will analyze the fluid to determine what kinds of cells are present and confirm whether or not the swelling is a sialocele. This analysis can also rule out infections, cancer, and other potential causes for the swelling.
Without treatment, sialoceles can become infected and abscessed. Contact your veterinarian if you notice any unusual swelling in the mouth or near the neck, jaw, or eye. Sialoceles typically require draining and then surgical intervention. Here are the two methods of treatment:
- Draining: In some cases, a sialocele can be drained to offer temporary relief until surgery can be performed. Most sialoceles will eventually recur after being drained. Continued draining is not recommended as it can lead to inflammation or infection.
- Surgery: Definitive treatment of sialoceles involves surgical removal of the affected salivary glands and associated ducts. This is a delicate procedure that is typically performed by a board-certified veterinary surgeon. Drains may be temporarily placed at the surgical site to prevent new fluid accumulation.
Prognosis for Dogs With Sialoceles
Most dogs recover well from salivary gland removal surgery with basic home care and complications are rare. Follow your veterinarian's recommendations for post-operative care. Give medications as directed. Keep the incision, drain sites, and any bandages clean and dry. Bring your dog back to the vet for follow-up visits as necessary.
How to Prevent Sialoceles
Sialoceles are rare, but dog owners can still take steps to prevent injuries that may lead to sialoceles. Here are a few ways to keep your dog healthy:
- Avoid using choke collars on your dog.
- Train your dog to walk on a loose leash to prevent injuries from pulling.
- Supervise your dog when gnawing on chews and toys,
- Keep your dog from chewing on sticks or other foreign objects.
Contact your veterinarian if you notice an injury to your dog's mouth or neck. Treatment of a fresh injury may prevent the development of a sialocele.