Finding a new lump on your dog can be scary. Any time you find a new lump or bump, it’s important to see your veterinarian to ensure it isn’t anything serious. But there’s good news: Not all lumps and bumps are cause for concern. Sebaceous cysts on dogs, the most common kind, are benign lumps that fall into that harmless category.

Knowing how to identify and address sebaceous cysts on your dog can help you be sure that your dog’s skin is staying as healthy as possible. Here’s everything you need to know about them.

What is a Sebaceous Cyst?

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Microscopic structures called sebaceous glands cover your dog’s skin. These glands are responsible for secreting sebum, an oily or waxy substance that lubricates the skin and hair shafts.  

A sebaceous cyst is a dilation (opening) of the ducts within the sebaceous gland, causing fluid to accumulate.  

True sebaceous cysts are rare in dogs, but veterinarians often use the term interchangeably with other types of cysts. Follicular cysts—sac-like structures often associated with the hair follicles—are much more common in dogs but are generally included under this catch-all term.

What Does a Sebaceous Cyst Look Like on a Dog?

A sebaceous cyst typically appears as a small, raised, well-defined round structure in the skin.  Usually these cysts are solitary, but some dogs may be prone to getting several cysts in the same area of the body.  

A sebaceous cyst may feel firm or filled with fluid. If infected, the cyst may appear red, inflamed, and painful. Sebaceous cysts can sometimes rupture and may discharge fluid, pus, or blood.

What Causes Sebaceous Cysts on Dogs?

In most cases, we don’t know what causes sebaceous cysts on dogs. Some dogs may be more prone to developing sebaceous cysts due to their genetics. Others may develop cysts due to skin infections, scar tissue, trauma, or inflammation. Fortunately, in most cases we do not need to know what caused the cyst in order to address it. 

Sebaceous Cyst Symptoms in Dogs

Most pet owners will first notice a sebaceous cyst when they discover a raised bump on their dog’s skin. The bump can range from 0.5 cm to 5 cm in size—about the size of a pea to the size of two quarters.  

A sebaceous cyst is typically slow-growing and may not bother the dog at all.  

Other signs of a sebaceous cyst can include:

• Swelling or redness around the area
• Pain
• Hair loss around the bump
• Pus or fluid discharge

Common Places Sebaceous Cysts Develop on Dogs

Sebaceous cysts can occur anywhere on the body, but may be more common along the head, neck, and back. Some dogs will develop multiple cysts along the ears or around the anus.  

Occasionally, sebaceous cysts can develop on pressure points like the hips and elbows, especially if the dog is frequently laying on hard surfaces.  

How to Diagnose a Sebaceous Cyst

Always discuss any new lumps and bumps with your veterinarian, who can appropriately diagnose them. Your veterinarian will perform a full physical examination on your dog, including assessing the location, size, and appearance of the bump.  

Your veterinarian may also recommend the following tests:

Fine Needle Aspirate and Cytology. Your veterinarian may recommend taking a sample from the bump using a needle and syringe. Your vet will examine it under a microscope and often can determine whether the bump is a cyst or a tumor based on this sample.

Biopsy. In some cases, a needle alone won’t successfully obtain a sample.  When this happens, your veterinarian may recommend surgically removing all or part of the bump and submitting it to a diagnostic laboratory for evaluation. This is usually the best way to get a definitive diagnosis.

Many pet health insurance providers, such as Lemonade, can help out with veterinary bills for diagnostics and treatments related to sebaceous cysts. The key is to ensure you’re covered before the issue is detected, which is why it’s so important to insure your pet when they are young. 

When to Worry About a Sebaceous Cyst

If the lump you find on your dog turns out to be a sebaceous cyst, there’s not much cause for concern. Often, these bumps will stay quiet and simply live as a blemish on your dog’s skin.

However, these cysts have the potential to rupture, which opens up the possibility for other complications. Whether caught by accident from your groomer’s clippers or after your dog scratches it too vigorously, the cyst can open and become infected.

It’s time to worry when you notice that the cyst has become red, inflamed, and/or starts emitting an unpleasant odor. Sebaceous cysts that have ruptured may bleed and produce discharge, both of which can be unpleasant to your pup. If you notice any of these symptoms, or if you notice your dog in pain, take him to your veterinarian immediately.

Dog Sebaceous Cyst Treatment

Cysts are typically benign and slow-growing, so treatment is often not needed. Your veterinarian may recommend simply monitoring the area.  

If the cyst is growing or bothering your dog, your vet may recommend surgery to remove it. It’s best not to try to pop these cysts at home. Doing so may cause inflammation and infection, and may be painful for your dog.

Medications to Treat Sebaceous Cysts on Dogs

In most cases, sebaceous cysts will not go away with medication alone.  The only way to definitively cure a sebaceous cyst is to surgically remove it.  However, your veterinarian may prescribe medication to help manage the problem if the cyst becomes infected. These medications may include:

Antibiotics. If your dog’s cyst is infected, your veterinarian may prescribe antibiotics to treat the infection. These may include pills or topical ointments.  You may notice that the cyst shrinks or that the discharge resolves once your dog has completed the antibiotic course.

Anti-inflammatories. If the cyst is inflamed or painful, your veterinarian may prescribe anti-inflammatory medications such as NSAIDs or steroids to help. These are typically prescribed as a pill, although your vet may recommend a topical steroid instead.  

General Cost to Treat Sebaceous Cysts

Sebaceous cysts often do not require any treatment at all, so they are very inexpensive to manage in most cases. Your veterinarian may recommend simply monitoring the cyst for any changes.  

If a sebaceous cyst is surgically removed, many pet health insurance plans, such as those offered by Lemonade, may help offset costs depending on your policy’s terms, conditions, and eligible conditions.

How to Prevent Sebaceous Cysts on Dogs

Unfortunately, there do not seem to be any effective ways to prevent sebaceous cysts in dogs.  Although we don’t know exactly what causes some dogs to develop sebaceous cysts, many experts believe genetics play a role.  

However, keeping your dogs skin and coat healthy with regular grooming is always a good idea for your dog’s comfort and overall health. 

Related Conditions

• Follicular cyst
• Dermoid sinus
• Sebaceous adenoma
• Nodular panniculitis