Skin Cysts (Follicular Cysts)

What is it?

Most skin cysts in dogs are malformations of hair follicles that fill with keratin, a skin protein. The contents are often gray, brown, or yellowish and cheesy. There are several types, named for the part of the follicle involved, such as infundibular follicular cysts. Dermoid cysts are a type present from birth, most often seen in Boxers, Kerry blue terriers, and Rhodesian ridgebacks.

What signs should I watch for?

Look for a single or several round lumps in or under the skin, often with a firm core. A cyst may open and release thick, cheesy material. A cyst that becomes red, swollen, or sore may be inflamed.

How is it diagnosed and treated?

Your veterinarian can usually recognize a cyst on examination, and a sample can rule out other lumps. Surgical removal is the best treatment. Do not try to squeeze a cyst: pushing the contents into the surrounding tissue can trigger severe inflammation, because the body reacts to the material as something foreign.

Can it be prevented, and what's the outlook?

• Skin cysts are benign and there is no known way to prevent them.
• Removed cysts usually do not cause further trouble, but new ones can appear.
• Have new lumps checked so other kinds of growths are not missed.