Sebaceous Cysts in Cats

Last Updated on March 9, 2021 by Julia Wilson


Sebaceous cysts (epidermal inclusion cysts) are benign tumours of the skin. They are the most common surface tumour found in cats and are composed of a thick, cheesy, yellow substance known as sebum, which is a secretion of the sebaceous gland comprised of fat and cellular debris, which lubricates and protects the skin.

Sebum originates from the sebaceous glands, which are tiny glands located within the hair follicle. Sebaceous cysts occur when the follicle becomes blocked, causing a build-up of sebum to occur. Left untreated, sebaceous cysts can become infected and therefore while the cysts themselves are harmless, they should be seen by a veterinarian.

There is no breed, age or sex predilection.


Smooth, soft fluid-filled lumps which may have a blue hue to them. Cysts can grow up to 1-2 inches in diameter. The most common areas to develop cysts are the head, neck, and trunk.

Occasionally they will rupture, oozing a thick paste-like yellow-grey substance.


Your veterinarian can make a tentative diagnosis based on physical examination. He may wish to perform a biopsy or a fine needle aspiration on the cyst to determine if it is a benign or malignant (cancerous) tumour.


Do not attempt to squeeze cysts yourself, if you notice any growths on your cat, seek veterinary attention.

  • Some veterinarians will apply a wait and see approach and leave the cyst alone. If this is the case, you will need to regularly monitor the cyst for signs of growth or infection.
  • In some cases, your veterinarian may drain the cyst.
  • Surgical excision of the cyst although new cysts may grow. Removal of the cyst will usually be by electrocautery or cryotherapy
  • Antibiotics to treat a secondary infection, if present.