Bump on Your Dog's Vulva: Cysts, Pimples, and When to Worry

Name: Bump on Your Dog's Vulva: Cysts, Pimples, and When to Worry
Creator: Dr. Zubair Khalid

By Dr. Zubair Khalid, DVM, MS, PhD · 2026-10-03

A dog bump on vulva is usually a benign skin problem such as a pimple, hair follicle infection, or cyst, but it can also be a tumor that needs veterinary testing. The only way to know which one you are dealing with is an exam, and often a sample of the cells. Some bumps are emergencies, so knowing the red flags matters.

This article is educational and is not a substitute for veterinary diagnosis or treatment.

Quick Answer

Most small bumps on the vulva are folliculitis, cysts, or irritation from skin folds, and these are treatable.
A bump that is growing fast, bleeding, ulcerated, or painful needs a veterinary visit right away.
Transmissible venereal tumor (TVT) is a contagious cancer spread between dogs during mating, and it appears as a raised, often cauliflower-like mass on the vulva.
Mast cell tumors and other skin cancers can look like harmless pimples, so a vet should sample any bump that does not resolve in a week or two.
Do not squeeze, pop, or apply human acne products to a bump on your dog's vulva.

What a Bump on the Vulva Looks Like and What Is Normal

The vulva is the external opening of the female reproductive tract. Around it sits a ring of skin, hair, and folds. In some dogs, those folds are prominent enough to partly cover the vulva. This is called a recessed vulva, also known as a hooded, juvenile, hypoplastic, or inverted vulva [1]. It is a conformation issue, meaning it is about body shape, not disease.

A recessed vulva itself is common. In one study of 250 female dogs at a referral hospital, 14% had a recessed vulva [2]. Dogs with recessed vulvas tended to have higher body condition scores and body weights, and the condition was more common in spayed dogs than in sexually intact dogs [2]. Most dogs with this shape develop related signs before one year of age, and medium to giant breeds are overrepresented [3].

That extra skin traps moisture, urine, and debris. The result is a warm, damp pocket where bacteria and yeast grow. This is why dogs with recessed vulvas get perivulvar dermatitis (red, irritated skin around the vulva), chronic urinary tract infections, vaginitis, and sometimes urinary incontinence [1][3].

Normal vulvar tissue is smooth, pink to pigmented, and symmetrical. It should not have a distinct raised lump, a discharge of pus, a foul odor, or an open sore. If you see any of those, something is going on.

Common Causes of a Dog Lump on the Vulva

Owners often describe these as a dog cyst on vulva, a dog pimple on vulva, or simply a bump they noticed while petting or grooming. Here are the main possibilities.

Cause	Typical clues	How urgent
Folliculitis (infected hair follicle)	Small red or white bump, often several, may have a pus head, tender	Routine, see vet within days
Cyst or blocked gland	Smooth, round, movable, skin-colored or slightly blue, slow growing	Routine
Perivulvar dermatitis from skin folds	Red, moist, smelly skin, licking, small bumps and crusts	Routine to urgent if infected
Abscess	Warm, painful, swollen, may drain pus	Same day
Transmissible venereal tumor (TVT)	Firm, raised, cauliflower-like mass, often bleeding or ulcerated, history of mating	Same day
Mast cell tumor	Raised lump that may change size, red, itchy, sometimes ulcerated	Same day to urgent
Other skin tumors (papilloma, Merkel cell carcinoma, others)	Variable appearance, may grow quickly	Same day to urgent
Vaginal or vulvar prolapse	Large pink tissue protruding from the vulva	Emergency

Folliculitis and Pimples

Folliculitis is inflammation of the hair follicle. It looks like acne in people: small red bumps, sometimes with white heads. On the vulva, this often happens because of moisture and friction from skin folds. A dog pimple on vulva is usually folliculitis until proven otherwise. Mild cases respond to keeping the area clean and dry, but if the bumps spread or your dog is uncomfortable, a vet visit is warranted.

Cysts and Blocked Glands

A dog cyst on vulva is typically a smooth, round, fluid-filled or firm sac under the skin. It may stay the same size for months. Cysts can become infected and turn into abscesses, which are painful and need drainage. Your vet can often tell a cyst from a solid tumor by feel, but not always. A fine needle sample helps.

Perivulvar Dermatitis and Skin Fold Problems

When the vulva is recessed, urine and moisture sit against the skin. That skin becomes red, thickened, and sometimes covered in small bumps, crusts, or pustules [1]. Dogs lick the area, which makes it worse. This is a common reason for a dog red bump on vulva or a cluster of bumps. Treating the infection and keeping the area dry helps, but some dogs need surgery to remove the extra folds, a procedure called vulvoplasty or episioplasty [3][4].

Transmissible Venereal Tumor (TVT)

TVT is a cancer that spreads between dogs through mating or direct contact with an affected dog's tumor. It appears as a raised, fleshy, often cauliflower-like mass on the vulva or penis. It can bleed and become secondarily infected. TVT is treatable, usually with chemotherapy, and many dogs do well. Because it is contagious, other dogs in the household or in contact with your dog may need evaluation.

Mast Cell Tumors and Other Cancers

Mast cell tumors are a common skin cancer in dogs. They can look like a pimple, a wart, or a raised red lump. They may change size, itch, or ulcerate. Because they release histamine and other compounds, they can cause local swelling and redness. Any lump that does not resolve, or that changes, should be sampled. Other tumors, including Merkel cell carcinoma, can also appear as a solitary growing mass and can be confused with less serious skin growths [5].

Red Flags That Make It an Emergency

Some signs mean you should not wait. Go to a veterinarian now if you see:

Heavy bleeding from the vulva or the bump
A large mass protruding from the vulva (possible prolapse)
Your dog straining to urinate, crying, or unable to pass urine
A rapidly growing lump that doubled in size in days
Open, ulcerated, or foul-smelling mass
Lethargy, fever, vomiting, or not eating
A bump that appeared after mating, especially if the other dog had a visible mass

These signs can point to infection, a bleeding tumor, or a blocked urinary tract. Waiting can make treatment harder.

Safe Things You Can Do at Home While Waiting

You cannot diagnose this at home, but you can keep your dog comfortable and avoid making it worse.

Do not squeeze, pop, or lance the bump. This can spread infection or cancer cells.
Do not apply human acne creams, hydrogen peroxide, or alcohol to the vulva. These irritate delicate tissue.
Keep the area clean and dry. Gently wipe with a damp cloth or pet-safe wipe, then pat dry.
Use an Elizabethan collar if your dog is licking the area. Licking causes more inflammation and can introduce bacteria.
Trim long hair around the vulva if it traps urine, but be careful with scissors near skin.
Take a photo with a ruler or coin next to the bump so you can track size changes.
Note when you first saw it, whether it has changed, and any other signs like licking, discharge, or accidents in the house.

If your dog is licking the vulva or paws excessively, that can be a sign of irritation or allergy. See Dog Licking Paws And Vulva for more on that behavior.

What the Veterinarian Will Check and Test

Your vet will start with a full physical exam, including a close look at the vulva and the skin folds around it. They will check for discharge, redness, swelling, and whether the vulva is recessed. They may also check your dog's body condition score, since higher body condition is linked to recessed vulva [2].

Common tests include:

Fine needle aspirate (FNA): A thin needle collects cells from the bump. This is quick, often done in the exam room, and can identify mast cell tumors, TVT, and other cell types.
Cytology of the vulvar skin: A swab or impression smear checks for bacteria, yeast, and inflammatory cells. Sampling site matters for vaginal cytology, so your vet will choose the right location [6].
Urinalysis and urine culture: If your dog has accidents, straining, or a history of urinary tract infections, this checks for infection and crystals.
Biopsy: A piece of the lump is sent to a lab for a definitive diagnosis. This is often needed for solid masses or when cytology is inconclusive.
Imaging: X-rays or ultrasound may be used if a tumor is suspected to have spread, or if a urinary tract problem is involved.

If the bump is a cyst or folliculitis, treatment may be as simple as medicated wipes, topical ointment, or oral antibiotics. Your vet will calculate any medication dose based on your dog's weight and health. If the bump is a tumor, the treatment depends on the type. Surgery is common for many skin tumors, and some cancers need chemotherapy or other drugs.

For a broader look at skin lumps in dogs, see Dog Skin Bumps and Lumps: When to See the Vet and Dog Skin Bumps: Comprehensive Veterinary Reference Guide.

Prevention and Monitoring

You cannot prevent every bump, but you can lower the risk of the most common ones.

Keep your dog at a healthy weight. Higher body condition scores are linked to recessed vulva, and extra weight adds friction and moisture [2].
Keep the vulvar area clean and dry, especially in dogs with skin folds.
Check the area weekly during grooming. Early detection makes treatment easier.
If your dog has a recessed vulva and repeated infections, ask your vet about vulvoplasty. In one study, 82% of owners rated the outcome of vulvoplasty as at least satisfactory, and urinary incontinence improved, though it remained the most common residual sign [3].
Spaying does not appear to cause recessed vulva, and prior spay did not influence the condition in one surgical case series [3]. However, recessed vulvas were more common in spayed dogs in a separate study [2]. The relationship is not fully settled.
If your dog has a history of mast cell tumors, your vet may recommend more frequent skin checks.

Monitor any bump for changes in size, color, texture, or discharge. A bump that stays the same for months is less worrying than one that changes in weeks. When in doubt, get it checked.

Limitations and When to Contact a Veterinarian

This article cannot tell you what your dog's bump is. Only a veterinarian who examines your dog and runs tests can do that. Individual cases vary, and some serious conditions look harmless at first.

Contact your veterinarian the same day if you see a new bump that is painful, warm, or draining pus. Go to an emergency clinic now if there is heavy bleeding, a large mass protruding from the vulva, or your dog cannot urinate. Schedule a routine visit within a few days for a small bump that is not changing and does not seem to bother your dog.

If you are unsure, call your vet's office and describe what you see. They can help you decide how soon your dog needs to be seen.

Frequently Asked Questions

Can I pop a pimple on my dog's vulva?

No. Popping or squeezing can push bacteria deeper, cause an abscess, or spread cancer cells if the bump is a tumor. Keep the area clean and let a veterinarian decide if it needs to be drained.

Is a bump on the vulva always cancer?

No. Most bumps are folliculitis, cysts, or irritation from skin folds. However, mast cell tumors, TVT, and other cancers can look like ordinary pimples, so testing is the only way to be sure.

How do I know if my dog's vulvar bump is a cyst or a tumor?

You cannot tell by looking or feeling alone. Cysts are often smooth and movable, while tumors can be firm or irregular, but there is a lot of overlap. A fine needle aspirate or biopsy gives the answer.

Should I spay my dog if she has a bump on her vulva?

Spaying is a separate decision from the bump. Spaying does not appear to cause recessed vulva in most studies, and it prevents other reproductive diseases. Talk to your vet about timing, especially if surgery is needed for the bump.

Can a dog bump on the vulva go away on its own?

Some mild cases of folliculitis or irritation improve with cleaning and drying. A bump that is still there after a week or two, or that grows or changes, needs a veterinary exam. Do not wait longer than that.

References

Recessed Vulva in Dogs - Reproductive System. Merck Veterinary Manual.
Characterization of recessed vulvas in dogs. Journal of the American Veterinary Medical Association, 2021.
Results of vulvoplasty for treatment of recessed vulva in dogs. Journal of the American Animal Hospital Association, 2002.
Perivulvar dermatitis in a cat treated by episioplasty. The Journal of small animal practice, 2005.
Diagnosis and treatment of Merkel cell carcinoma in a puppy: A comparative oncology approach. The Canadian veterinary journal = La revue veterinaire canadienne, 2026.
Methodological Factors Affecting Canine Vaginal Cytology: The Influence of Sampling Site, Swab Condition, and Fixation Method. Veterinary medicine international, 2026.