Why Does My Dog Develop Sebaceous Cysts?

Posted on June 23rd, 2015
A sebaceous cyst develops from a sebaceous gland. What is a sebaceous gland?

A sebaceous gland is a small gland that resides in the skin of you and your dog.

Its function is to produce an oily substance referred to as sebum.

The purpose of the sebum is to lubricate the hair follicle, hair shaft and also produce protective oils for the skin.

If this oil production of sebum continues, but its exit for release is blocked, the sebum will begin to build and produce a mucous membrane structure that slowly fills up. The end product is a yellow to white material that resembles cottage cheese.


In people, when this process begins it is referred to as a “clogged pore”.

The cause of a sebaceous cyst can come from a swollen hair follicle, due to a localized inflammatory reaction from an insect bite, from an allergic dermatitis, from trauma to the skin, or a hormonal imbalance.


What are the clinical signs of a sebaceous cyst?

The following clinical signs may be present:

  • A raised area of skin resembling a swelling or tumor.
  • It may be a well-defined mass that is freely movable.
  • It may be possibly inflamed.
  • If the sebaceous cyst has been open and draining for a while, it may secrete infected and or cyst material.
  • If the sebaceous cyst has freshly ruptured, expect to see a yellow to white cottage cheese like material being extruded.


There may be different treatments that will determined by the stage of development of the sebaceous cyst.

STAGE 1 is when the sebaceous cyst is just beginning to develop on the surface of the skin.

Your choices may be:

  • Merely watch the area to see if it does grow in size.
  • Have a needle aspirate done to identify the material within the cyst.
  • Have the cyst removed surgically and if there is a problem identifying what has   been removed, send the specimen into a veterinary laboratory for identification.

STAGE 2 is when the cyst has matured.

Your choices may be:

  • Surgically have the cyst opened and drained and treat with topical antibiotics. Please remember however, the mucous membrane around the cyst is secretory and if it still remains, the cyst may reoccur.

STAGE 3 is when the cyst has ruptured to the outside of the skin.

Your choices may be:

  • Have your veterinarian first treat any inflammation or infection that might be present.
  • Possibly carefully have your veterinarian digitally and safely empty as much sebaceous material as possible.

Once this has been done and the cyst becomes quiescent, have the cyst surgically removed, and if the contents cannot be identified, send the tissue to a veterinary laboratory for identification.

STAGE 4 is when the sebaceous cyst has ruptured and exited into the tissue beneath the skin.

Your choices may be:

  • Have your veterinarian treat the ruptured sebaceous cyst until the cyst has become less inflamed and less infected.

A two-step procedure may be indicated next.

  • The area is surgically opened and as much sebaceous cyst material is removed as possible, and a drain is placed in the ruptured area of skin to help with further draining of inflammatory and cyst materials.
  • Once the drain has been removed and the sebaceous cyst has been reduced in size and is better defined, surgical excision is indicated.

Please remember, your best source for treatment information will come from your veterinarian!


Sebaceous cysts in dogs are very common, and especially are very common in many specific breeds of dog.

Genetics seem to be the main cause of sebaceous cysts which often occur in a family of dogs. Often lipomas will also follow the development of sebaceous cysts in certain breeds of dogs.

Your veterinarian will help you identify those breeds that seem to be the most susceptible to developing sebaceous cysts.

In humans, there may a genetic base. Also, the literature indicates human patients with elevated testosterone levels seem to be prone to developing sebaceous cysts.

My clinical research studies have indicated that elevated adrenal estrogen or total estrogen is the major cause of sebaceous cysts in dogs.

If you dog seems to be prone to developing sebaceous cysts, there is a simple endocrine immune (hormone antibody) blood test that will help you decide if the production of ongoing sebaceous cysts in your dog is caused by a hormonal antibody imbalance.

For further information on this blood test please visit Laboratory Information.

Hopefully this article will help you to decide on the best medical direction to take in order to help your dog with a sebaceous cyst and also stop further sebaceous cysts from developing.


Dr. AL Plechner