Mumps in Dogs (Cervical Sialocele)

The term "mumps" and salivary disorders aren't as widespread in veterinary medicine as they are in human medicine. In veterinary medicine, it's called mucocele or sialocele.

This is an abnormal filling of saliva in an area, coming from the salivary glands. Below, at Soyunperro we'll take a closer look at what it is, what causes it, what its symptoms are, as well as its treatment. Let's begin.

Types of Salivary Glands in Dogs

To understand "mumps," or more scientifically called mucocele or sialocele, we need to know about the salivary glands dogs have. So, there's the parotid salivary gland (below the base of the ear), the mandibular gland (body of the jaw), the sublingual (under the tongue), and the zygomatic (under the eye).

What Is a Sialocele and Which Gland Is Affected in "Mumps"?

A salivary mucocele or sialocele is defined as the buildup, at the subcutaneous tissue level, of saliva coming from a damaged salivary gland or duct, generating a significant tissue reaction (granulation tissue) in the area. Depending on its location, different clinical presentations of a sialocele are described.

Most affected animals have a fluctuant, painless mass. Although in the early stages, the mass is firm and can be painful. It affects dogs more than cats. Regarding "mumps," the affected gland giving rise to it is usually the sublingual one. This is then called cervical sialocele. Saliva builds up in the deeper structures of the intermandibular space. This is the most common form of sialocele.

Causes of Sialocele

The most likely causes of mucocele are trauma or individual congenital predisposition, with the latter being the most likely. It normally occurs in dogs 2 to 4 years old, with a higher predisposition in German Shepherds and Poodles, but it can affect many more breeds.

Although the main cause of mucocele in dogs is trauma, the presence of a sialolith, foreign body, or neoplasm as a causative agent can't be ruled out.

Sialolithiasis, meaning the presence of a salivary stone as the cause of a cervical sialocele, is a very uncommon finding. In most cases, the presence of a sialolith causes rupture and subsequent fibrosis of the salivary ducts, allowing saliva to leak into nearby tissue, building up in the lowest-lying areas relative to the glands.

Symptoms of Sialocele

Symptoms will vary to a greater or lesser degree depending on which gland is affected. We'll focus on cervical mucocele or sialocele, or "mumps."

As mentioned earlier, in cervical mucocele there's a sudden, painful swelling in the intermandibular area, which can initially improve without treatment (acute mucocele), and in some cases present as a non-painful, chronic swelling that alternately improves and worsens (chronic mucocele).

In chronic cases, sialoliths that can be felt from outside often form. Symptoms can include:

• Difficulty grasping food.
• Presence of blood in the saliva.
• Mouth pain.
• Possible loss of appetite.
• Besides the mass, it's possible for no other symptom to be detected.

Sialocele Diagnosis

Clinical diagnosis of cervical mucocele or sialocele is based on detecting a soft, fluctuant mass near the gland, at the intermandibular region level. After puncturing and aspirating it, a yellow or slightly bloody, viscous, mucoid fluid with scarce cellularity under microscopic study is obtained.

However, to detect sialoliths, imaging tests such as X-rays or ultrasound are needed.

Treatment for Cervical Sialocele

In cervical mucocele, the treatment of choice is complete excision of the sublingual and mandibular salivary gland along with drainage of the mucocele using a Penrose drain. A histopathological diagnosis of the removed glandular tissue can be made after sending it to the lab following surgery.

Excision or drainage of the cervical mucocele as the sole treatment has a high recurrence rate, meaning it can come back. Standalone drug treatment isn't recommended, especially not decided on by the owner, since your furry friend could get worse or fail to fully improve.

Bibliography Estudio mucocele salival cervical ocasionado por un sialolito en un perro. M.E. Lebrero-Berna, E. Ramón-Soláns, M. Alamán-Valtierra, A. Unzueta-Galarza, A. González-Inglán. Hospital Veterinario de la Universidad de Zaragoza. Published in AVEPA. Some information also taken from the surgery course, digestive system surgery section, taught at Universidad Alfonso X el Sabio.