How to diagnose and treat sebaceous cysts in dogs

If you find a lump on your dog, it’s easy to be concerned. But don’t fret—it might be a sebaceous cyst. While annoying, these cysts aren’t harmful. We explore what they are, how they form, and how they’re diagnosed and treated.

Sebaceous cysts are swelling underneath the skin caused by clogged oil glands. They can be found on dogs of any age and breed and are fairly common.

All dogs have sebaceous glands (sweat glands) that secrete keratin. Sebaceous glands play an important role in keeping your dog’s coat sleek and shiny. Brushing your dog prompts these glands to release the keratin oils that moisturize your dog’s skin. The hair follicles of these sebaceous glands can get blocked, which causes a buildup of oil secretions. When the sebaceous gland remains blocked, the natural secretions have nowhere to go, prompting a cyst to form. In short, sebaceous cysts are swelling in the skin caused by a clogged sebaceous gland.

These cysts are also known as epidermoid or epidermal inclusion cysts. However, they aren’t the most common cysts dogs can have. Follicular cysts are more common in dogs. Follicular cysts are lumps that form in the sacs under hair follicles.

Cancerous sebaceous cysts

Many sebaceous cysts are benign, but there’s a chance they can interfere with your dog’s natural movement and are also prone to infections.

In some cases, these cysts can be a sign of an underlying condition, like cancer. Dogs can get a variety of skin cancers, including malignant melanomas, mast cell tumors, squamous cell carcinomas, and more. As with any change to your dog’s health, if you notice a new lump or bump, especially one that grows in size or is hard with angular, irregular shaping, seek vet care.

There are many reasons why your dog may develop a cyst and many of them are completely harmless. Some of these causes include:

Genetic predisposition

Some breeds, including Schnauzers and Yorkshire Terriers, could be genetically predisposed to developing cysts.

Follicle opening blockage

Clogged glands cause sebaceous cysts. This could be because of oil trapped in the glands, but injuries, dirt, and infections can also lead to clogged pores, creating cysts.

Injury or trauma

Sometimes, sebaceous cysts can form because of trauma. Trauma can include anything from scratches, bites, and surgical wounds to skin lacerations.

Age

Different types of sebaceous cysts that can be found in older dogs or specific breeds. Sebaceous gland adenocarcinoma is a malignant cyst found in middle-aged and older dogs. These malignant cysts are more likely to be found in male dogs. They’re also more likely to happen in breeds like Cavalier King Charles Spaniels, Cocker Spaniels, or Scottish, Cairn, and West Highland White Terriers.

Sebaceous gland adenoma (a rare, benign lesion) can be found in older dogs, typically on the dog’s head. Some breeds are predisposed to sebaceous adenoma, including Samoyeds, Siberian Huskies, and Alaskan Malamute.

The appearance of sebaceous cysts in dogs can vary, but in general, they range from half an inch to approximately two inches (though cysts this large are rare). That’s the size of a blueberry compared to the length of a credit card.

The cysts typically feel soft or firm and moveable on a dog’s skin or inside the skin layers. Cysts may look like pimples, warts, or slightly translucent nodules.

• Raised bump or lump
• Swelling
• Redness
• Pain
• Hair loss around the lump
• Fluid discharge
• Infection
• Bleeding
• Multiple bumps

Don’t squeeze or move these cysts. Popping a cyst can spread the cyst’s contents into the surrounding tissue, which can result in swelling, infection, or inflammation.

Dogs need to have their cysts checked out for the same reason that humans have moles and breast lumps checked out: while the cysts could be benign, there’s always a chance that it could be something serious.

Cysts can also interfere with a dog’s normal movement and impair them. A cyst on a paw pad, leg, or joint can interfere with their ability to walk. A cyst on an eyelid (known as meibomian gland adenoma) Trusted Source This is an approved Trusted Source for betterpet. Learn more about Trusted Sources can interfere with their ability to blink or cause excessive blinking.

While most cysts are generally slow-growing and aren’t harmful, cysts that grow quickly are abnormal. They can also rupture and lead to infection. It’s also important to go to the vet because some cancers may look innocent enough, but are actually malignant tumors.

👉 If you think your dog has a sebaceous cyst, visit your veterinarian.

Veterinarians will begin by giving your dog a complete physical examination. They will assess the size, appearance, and location cysts and check to determine if there are multiple cysts. Following that, your veterinarian has a few options to diagnose the bump.

Fine needle aspiration

Your veterinarian may use a fine needle aspirate to sample the raised bump with a needle and syringe. The  sample is then observed under a microscope to determine if the new lump is a cyst, tumor, or benign growth. However, fine needle aspiration may not be enough to make a definitive diagnosis. Vets will sometimes send these cells to lab specialists for more information.

Tissue biopsy

Another option is a biopsy Trusted Source This is an approved Trusted Source for betterpet. Learn more about Trusted Sources for a more accurate diagnosis. A biopsy is a surgical removal procedure where your veterinarian removes tissue that’s sent to a histopathologist and analyzed. For small bumps, your veterinarian will put your dog under local anesthesia and mild sedation. Larger biopsies will require general anesthesia. Histopathology is an effective way to determine what the new lump on your dog’s skin means. Biopsies can rule out other skin conditions, like lipomas or viral warts like papillomas.

Your veterinarian will also check for any infections or inflammation and provide treatment, sometimes with medication.

You can’t treat sebaceous cysts at home; the underlying condition that causes these cysts will need to be investigated. If you notice a new lump, your veterinarian may choose to observe and delay treatment until there’s further growth. Cysts are often benign, so treatment may not be needed. As long as the cysts aren’t bothersome, your veterinarian may prefer to keep an eye on it.

If it continues to grow or alters your dog’s movements of lifestyle,  your veterinarian may remove the cyst later on and treat the area with medication. Veterinarians may remove cysts through surgery. If there are multiple cysts, removal may take longer, and new sebaceous cysts may appear in the future, even after removal.

However, if the cyst is cancerous or a malignant adenocarcinoma, veterinary oncologists may start your dog with chemotherapy, Trusted Source This is an approved Trusted Source for betterpet. Learn more about Trusted Sources radiation, Trusted Source This is an approved Trusted Source for betterpet. Learn more about Trusted Sources and surgery.

👉 Never try to pop your dog’s cysts at home. This could cause skin infections or inflammation.

Your beloved canine may need to wear a cone or Elizabethan collar to prevent them from licking or biting the affected areas should they require surgery. You may need to give your dog antibiotics or apply any topical medication your veterinarian prescribes. You should check the wound’s location for redness and bleeding, and check in with your veterinarian if it doesn’t heal. While the wound heals, dogs shouldn’t be bathed and may be on strict rest.

If no surgery is needed, your vet may advise keeping the area clean and watching for growth.

There’s no way to effectively prevent sebaceous cysts, especially since genetics may determine which breeds are more likely to get them.

One of the best ways to monitor your dog’s health is also one of the simplest: brush your dog frequently. Frequent brushing keeps your dog’s skin and coat healthy and stimulates the sebaceous glands to release keratin. Stimulating the sebaceous glands can help prevent cyst growth as it helps reduce the chances of these glands becoming clogged.

While there is no definitive way to prevent sebaceous cysts from forming, there are ways to stay vigilant and informed should you notice one.