Salivary Mucocele

A salivary mucocele forms when saliva leaks from a damaged salivary gland or duct and collects in the surrounding tissue, creating a fluid-filled swelling. The body walls off this pooled saliva with a soft tissue lining, forming what is sometimes called a pseudocyst. The swelling can appear in different locations depending on which gland is affected—most commonly under the tongue, beneath the jaw, or along the side of the neck. Owners often notice a soft, fluctuant lump that may develop gradually or appear quite suddenly. The swelling itself is typically painless, though it can interfere with eating or swallowing if it becomes large or is positioned under the tongue. Some animals may drool more than usual, hold their head in an unusual position, or show difficulty closing the mouth comfortably. This page explores the signs that may prompt concern, what is happening beneath the surface to cause saliva to accumulate, how the condition is investigated and confirmed, and the range of approaches used to address it. The underlying cause of the initial leakage is often not identified, even after investigation.