Cysts in dogs and cats are hollow sacs that containing liquid or solid material.  Some tumors have centers that are cystic, but this discussion covers only cysts that are not cancerous. Common cysts in pets include follicular cysts, sweat gland cysts, congenital cysts, and cysts secondary to trauma.  Follicular cysts are particularly prone to secondary infection by bacteria.

Cysts usually appear in dogs and cats as soft, fluid-filled swellings under the skin that are not fixed, ie, they can be moved around in a small area.  Typically, cysts are not painful.  Cysts occasionally rupture, resulting in infected and inflamed tissues in the area.

Your veterinarian may be able to drain your pet's cyst by inserting a needle and drawing out the fluid.  However, cysts typically re-fill after being drained.  A sample of the fluid can be examined under the microscope to try and identify the type of cyst.  A biopsy may be needed to confirm the diagnosis.

Infected cysts in pets can be treated with antibiotics, but surgery to remove the cyst is generally needed to prevent it from recurring.  Other treatments may be necessary if there is a primary or underlying cause of the cysts.  Cysts caused by trauma usually resolve with time.

Q&A

What are skin cysts in pets?

Cysts are hollow sacs in the skin that contain liquid or solid material. 

Is this a form of cancer?

No.  Some tumors have cystic centers, but skin cysts are generally not cancerous.

How are cysts treated in pets?

Your vet may be able to drain the cyst, but the problem usually recurs.  Permanent cure usually requires surgery to remove the cyst, with antibiotics sometimes needed to combat secondary infection.

Written and reviewed by John A. Bukowski, DVM, MPH, PhD
and Susan E. Aiello, DVM, ELS