Salivary Mucocoele is the collection of saliva beneath the skin from a rupture of a duct of one of the salivary glands. Usually this appears as a swelling behind the lower jaw, and is usually more towards one side. Dogs have 8 salivary glands four on each side of their face. The glands that are usually associated with the condition are either the submandibular or sublingual glands.
Simply draining the collection of saliva will not solve the problem. Most often, removal of the affected glands is necessary in order to address the existing problem, and to prevent reocurance. Removing these glands is not a problem for the dog, as they have more than enough glands remaining to produce saliva.
Ocassionally, the duct will rupture as it passes through the mouth, beneath the tongue, and saliva will collect there. A ranula appears as a swelling beneath the tongue, and is usually confined to one side of the tongue. This is called a ranula. Similarly, the glands need to be removed in order to prevent reocurrance.