Cysts are hollow sacs containing liquid or solid material.
Some tumors have cystic centers, but this discussion covers only cysts that are not cancerous. Common cysts in dogs include:
- follicular cysts
- sebaceous cysts
- congenital cysts
- and cysts secondary to trauma
Follicular cysts are particularly susceptible to secondary infection by bacteria.
These cysts present as single bumps or nodules that originate from the hair follicle. As they grow, they can itch, hurt, and ooze trick material. They don’t invade beyond the skin but can become infected.
Further information: Follicular Cysts in Dogs
Sebaceous cysts are the most common skin growths in dogs. They can develop when the sebaceous gland is overactive or plugged. This can often happen in response to injury or inflammation of the skin.
Further information: Sebaceous Cyst in Dogs: Appearance, Diagnosis, and Treatment
What does a cyst look like?
Cysts usually appear as soft, fluid-filled swellings under the skin. They are not fixed, i.e., you can move them 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 dog’s cyst by inserting a needle and drawing out the fluid. However, after draining, cysts typically re-fill.
Your veterinarian can examine a sample of the removed fluid under the microscope. This can help identify the type of cyst. However, a conclusive diagnosis might require a biopsy.
Infected cysts can respond to antibiotic treatment. However, your dog will likely need to have it surgically removed to prevent a recurrence.
Other treatments may be necessary if there is a primary or underlying cause of the cysts. Cysts caused by trauma usually resolve with time.
Symptoms to Watch for in Your Dog: What Is that Bump?