Dog Skin Tag or Tumor? How to Tell and What to Do

By Dr. Zubair Khalid, DVM, MS, PhD · 2026-08-14

Key Takeaways

• Definitive diagnosis of skin growths in dogs, distinguishing benign from malignant, necessitates professional veterinary examination and often laboratory testing, such as fine needle aspirates or biopsies, as visual inspection alone is insufficient.
• Urgent veterinary care is required for growths exhibiting signs of severe bleeding unresponsive to pressure, rapid swelling of the head/neck, difficulty breathing, collapse, or seizures, indicating potential life-threatening conditions.
• Growths that have doubled in size within a week, are ulcerated, cause constant irritation (chewing, licking, scratching), or are painful warrant a same-day veterinary appointment for prompt evaluation.
• Benign growths like skin tags (acrochordons) are typically slow-growing, soft, and may not require removal unless they cause irritation or are located in problematic areas, while malignant tumors like mast cell tumors can vary significantly in appearance and growth rate.
• Home remedies, attempts at self-removal, or applying human medications to skin growths are strongly discouraged due to the risk of pain, infection, bleeding, and obscuring diagnostic findings for veterinary professionals.
• Regular self-monitoring of skin growths, including measurement and photographic documentation, coupled with prompt veterinary consultation for any changes in size, shape, color, or new lesion development, is crucial for early detection and appropriate management.

You found a lump on your dog and now you are worried. That is completely understandable. Most skin growths on dogs are benign, meaning they are not cancerous and do not spread. But some growths are malignant, meaning they can invade tissue or spread to other parts of the body. The only way to know for certain what a growth is, in many cases, is to have a veterinarian examine it and, often, test a sample of the cells.

Do not panic, but do take this seriously. Start by looking at the growth closely, note its size, shape, and color, and write down the date you first noticed it. Then read on to learn what you are seeing and when you need to act. If your dog is bleeding heavily from a growth, cannot breathe, collapses, or has a sudden, severe swelling, stop reading and go to an emergency veterinarian immediately.

Is This an Emergency?

Use this table to decide how quickly your dog needs care. When in doubt, call your regular veterinarian. They know your dog and can give you specific advice.

{
 "type": "triage",
 "title": "Urgency triage by severity of signs",
 "tiers": [
  {
   "tier": "danger",
   "label": "Go to an emergency vet now",
   "signs": [
    "A growth that is bleeding heavily and will not stop with firm pressure",
    "Sudden, rapid swelling of the face, neck, or throat",
    "Difficulty breathing",
    "Collapse or extreme weakness"
   ],
   "action": [
    "Do not wait for an appointment",
    "Go to the nearest open emergency clinic immediately"
   ]
  },
  {
   "tier": "warn",
   "label": "Book a same-day appointment",
   "signs": [
    "A growth that has doubled in size in a week or less",
    "A growth that is ulcerated, meaning the surface is broken open, oozing, or crusted",
    "A growth that your dog is chewing, licking, or scratching constantly",
    "A growth that is painful when touched"
   ],
   "action": [
    "Call your veterinarian first thing in the morning",
    "Explain what you see",
    "They will fit you in that day"
   ]
  },
  {
   "tier": "safe",
   "label": "Watch at home for a defined period",
   "signs": [
    "A small, soft, slow-growing lump that has been present for months or years",
    "A lump that looks like a narrow stalk with a round end, often called a skin tag",
    "No bleeding, no pain, no rapid change"
   ],
   "action": [
    "Measure the growth with a ruler and photograph it",
    "Check it weekly for one month",
    "If it changes size, shape, or color, or if new growths appear, book an appointment"
   ]
  }
 ]
}

What Is a Skin Tag?

A skin tag, which veterinarians call an acrochordon, is a small, soft, fleshy growth that hangs off the skin. It often looks like a tiny grape on a stem, or a piece of soft, wrinkled skin attached by a narrow base. Skin tags are usually the same color as your dog's skin or slightly darker. They are typically less than half an inch across, though some grow larger. They are almost always benign.

Skin tags can appear anywhere, but they are common in areas where skin rubs against skin or against a collar. You might find them on the neck, under the front legs, in the armpits, or on the chest. They are more frequent in older dogs and in larger breeds. A skin tag does not usually hurt, bleed, or grow quickly. If it stays the same for months, it is very likely harmless.

What Else Could This Growth Be?

A skin tag is only one possibility. Several other types of growths are common in dogs, and some look similar to skin tags at first glance.

A sebaceous adenoma is a benign growth of the oil glands in the skin. It often looks like a small, firm, cauliflower-shaped bump, sometimes with a waxy surface. These are common in older dogs and are not dangerous.

A histiocytoma is a benign growth of immune cells. It often appears suddenly as a small, round, red, button-like bump, usually on a young dog. These growths often go away on their own within a few months, but they can look alarming because they appear fast.

A mast cell tumor is a malignant growth of immune cells. This is the one that worries veterinarians most. Mast cell tumors can look like almost anything, from a small, innocent bump to a large, ulcerated mass. They can grow quickly, change size, and feel firm or soft. They can also release chemicals that cause redness, swelling, or itching around the growth. This is why any new or changing growth deserves a professional look.

Other possibilities include warts caused by a virus, cysts filled with fluid or debris, and lipomas, which are benign fatty tumors that feel soft and move easily under the skin. The American Veterinary Medical Association advises that any new lump on your dog should be checked by a veterinarian, because appearance alone is not enough to tell benign from malignant growths. The MSD Veterinary Manual for pet owners similarly notes that a definitive diagnosis of a skin mass usually requires laboratory testing.

When a Biopsy Is Needed

A veterinarian can often get a strong clue about a growth just by feeling it and looking at it. But feeling and looking are not enough for a diagnosis. The most common first test is a fine needle aspirate. The veterinarian inserts a small needle into the growth and withdraws some cells. Those cells are placed on a slide and examined under a microscope. This test is quick, usually painless, and does not require sedation in most dogs.

Sometimes the aspirate is not conclusive. The cells may be too few, or the growth may be a type that does not shed cells easily. In that case, the veterinarian may recommend a biopsy. A biopsy means removing a piece of the growth, or the whole growth, and sending it to a laboratory for a pathologist to examine. A pathologist is a specialist who looks at tissue under a microscope to determine exactly what it is and whether it is cancerous.

A biopsy is the only way to know for certain whether a growth is benign or malignant. This matters because treatment is completely different for the two. A benign skin tag needs no treatment at all. A malignant tumor may need surgery with wide margins, meaning the veterinarian removes the tumor plus a border of healthy tissue around it, to reduce the chance of it coming back. Some cancers also require chemotherapy or radiation. Guessing wrong about a growth can cost time, money, and, in the worst case, your dog's life.

What About Skin Tag Removal?

If the growth is confirmed as a benign skin tag, removal is usually optional. Many dogs live their whole lives with skin tags and never have a problem. You might choose to have one removed if it is in a spot where it gets caught on collars or harnesses, if it bleeds from rubbing, or if your dog keeps scratching at it.

Do not try to remove a skin tag at home. Tying a string around it, cutting it with scissors, or using any over-the-counter product can cause pain, bleeding, and infection. It can also make it impossible for a veterinarian to tell what the growth originally was. If removal is needed, your veterinarian will do it safely, usually with a quick procedure under local anesthesia or light sedation. The World Small Animal Veterinary Association provides global dermatology resources that emphasize the importance of professional diagnosis and treatment for skin conditions.

A Special Note on Eyelid Growths

A growth on the eyelid needs special attention. The eyelid is delicate, and a growth there can rub against the eye, causing pain, tearing, or damage to the cornea, which is the clear front surface of the eye. Even a benign growth on the eyelid may need removal because of where it sits. Do not wait to have an eyelid growth checked. Book an appointment with your veterinarian, who may refer you to a veterinary ophthalmologist, a specialist in eye care, if the growth is complex.

Your job right now is simple. Look at the growth, measure it, photograph it, and write down the date. Then call your veterinarian and describe what you see. They will tell you whether to come in today, this week, or to keep watching at home. Trust their judgment. You are not overreacting by asking. Catching a problem early is the single best thing you can do for your dog.

What You Can Do at Home Right Now

Start by leaving the growth alone. Do not pull, twist, clip, or tie anything around it. Do not apply creams, oils, vinegar, or any home remedy. These actions can tear the skin, introduce infection, or turn a harmless growth into a painful wound. If the growth is bleeding, press a clean cloth on it with steady pressure for five minutes. If bleeding does not stop, call your veterinarian immediately.

Keep an eye on the area but do not obsess over it. Check the growth once a day at the same time, perhaps during meals or brushing. Look for changes in size, shape, or color. Watch for new bleeding, crusting, or a foul smell. If your dog licks or chews the spot, use an Elizabethan collar, often called a cone, to prevent irritation. Your veterinarian can help you choose the right fit.

Do not try to measure the growth with a ruler while your dog is moving. Wait until your dog is relaxed or sleeping. A gentle approach works best. If your dog resists, stop and try later. Forcing the issue can make your dog fearful of handling.

What to Write Down Before You Call

A few minutes of observation can save time and help your veterinarian give better advice. Write down the answers to these questions:

• When did you first notice the growth?
• Has it changed since you found it? In what way?
• Is it raised, flat, smooth, rough, or cauliflower-like?
• What color is it? Pink, black, red, or flesh-toned?
• Is it attached by a narrow stalk or sitting directly on the skin?
• Does it bleed, ooze, or crust over?
• Does your dog lick, bite, or scratch at it?
• Are there other growths anywhere else on the body?
• Has your dog had any weight loss, appetite change, vomiting, or diarrhea?

Take two photos in good light. One photo should show the growth from a distance so the location is clear. The other should be close up. Place a coin next to the growth for scale. These photos help your veterinarian and are useful for tracking changes over time.

Comparison Table: Common Dog Skin Growths

This table is a starting point, not a diagnosis. Many growths look alike. A mast cell tumor can look exactly like a harmless skin tag in its early stages. That is why a veterinarian's hands and, when needed, a microscope matter.

What a Veterinary Visit Looks Like

Your veterinarian will start with a full physical exam. They will feel the growth and check the lymph nodes, which are small glands under the jaw, behind the knees, and in front of the shoulders. They will look for other growths across the body. They will ask about your dog's appetite, energy, and bathroom habits.

The most common test is a fine needle aspirate. The veterinarian inserts a thin needle into the growth and withdraws a few cells. This is quick and usually does not require sedation. The cells are placed on a slide and examined under a microscope. This test can often tell whether the growth is fatty, cystic, inflammatory, or made of mast cells, which are immune cells linked to allergic reactions and some tumors.

If the aspirate is unclear, or if the growth looks aggressive, a biopsy may be recommended. A biopsy removes a small piece or the entire growth for laboratory analysis. This requires sedation or anesthesia. The results take a few days.

Costs vary widely by region and clinic. A fine needle aspirate might range from 50 to 150 dollars. A biopsy with anesthesia might range from 300 to 800 dollars. Full surgical removal with histopathology, which is a detailed lab review of the removed tissue, can range from 500 to 1,500 dollars. These are rough figures only. Ask your clinic for an estimate before any procedure.

When an Online Vet Can Help, and When It Cannot

Some situations in this article require hands-on care and must not be handled remotely. If your dog has a growth that is bleeding heavily, growing rapidly, or causing pain, you need an in-person visit. If your dog is lethargic, vomiting, or has a swollen abdomen, go to an emergency clinic. If the growth is on the eyelid and touches the eye, or if your dog is squinting or rubbing the eye, that needs immediate in-person attention. No video call can replace a veterinarian's fingers on the tissue or a microscope on the cells.

A remote consultation is genuinely useful for early or mild presentations. If you just noticed a small, stable growth and want to know whether it warrants a visit, an online vet can help you decide. If your dog has a known skin tag that has not changed, a video check can provide reassurance. If your dog is recovering from a procedure and you have a question about the incision, a remote visit works well. If your dog started a new medication and you are unsure about a side effect, an online vet can advise.

A remote veterinarian can take a history, look at visible signs on video, and offer guidance. In many states they can prescribe medication. But they cannot palpate the abdomen, listen to the chest, take a temperature, run bloodwork, or image anything. They cannot feel whether a lump is attached to deeper tissue. They cannot tell you with certainty what a growth is. Prescribing rules differ by state, and a veterinarian may require an in-person examination before prescribing. Use remote care as a triage tool, not a replacement for diagnosis.

Your Vet-Visit Checklist

Bring these items to your appointment:

• Your written notes from the questions above
• Your two photos with a coin for scale
• A list of any medications your dog takes
• A record of any recent weight changes
• A list of any other growths you have found
• Your dog's vaccination history, if available

Ask your veterinarian these questions:

• What do you think this growth is?
• Do we need a test to confirm?
• What are the risks of leaving it alone?
• What are the risks of removing it?
• How long will recovery take?
• What should I watch for after the procedure?

A calm, prepared visit makes the process easier for you and your dog. Most skin growths in dogs are benign. But the only way to know for certain is to have a veterinarian examine the growth and, when indicated, test the cells. The American Veterinary Medical Association offers general guidance on working with your veterinarian and understanding common procedures. The MSD Veterinary Manual Pet Owner Version provides clear descriptions of skin conditions in dogs. Use these resources to prepare, not to diagnose. Your veterinarian remains the best source of advice for your individual dog.

Common Mistakes Owners Make With Skin Growths

Many owners mean well, but a few well-intentioned habits can delay care or cause harm. The most common mistake is waiting to see if a growth changes before calling the vet. A growth that grows slowly over months is often benign, but a growth that doubles in size in two weeks needs attention now. Another frequent error is trying to remove a skin tag at home with scissors, string, or a nail clipper. This can cause bleeding, infection, and severe pain. It also removes the tissue before a vet can examine it, which makes diagnosis harder.

Owners also mistake one growth for another. A tick can look exactly like a small skin tag, especially when engorged. A mast cell tumor, a type of skin cancer, can swell and shrink over hours, which owners often misread as a harmless bump that comes and goes. Do not assume a growth is benign because it does not bother your dog. Many tumors are not painful in early stages.

The better approach is simple. Mark the growth with a photo and a ruler in the frame. Check it weekly for changes in size, shape, color, or texture. If it bleeds, ulcerates, or grows quickly, call your vet that day. Never attempt removal at home. Let a professional decide whether a growth needs testing or removal. The American Veterinary Medical Association offers guidance on when to seek veterinary care for skin changes.

How to Reduce the Chance of New Growths

You cannot fully prevent skin tags or tumors. Genetics and age play large roles. But you can reduce some risks. Keep your dog at a healthy weight, since obesity is linked to skin fold irritation and inflammation. Brush your dog regularly and run your hands over the skin to find new bumps early. Check the ears, armpits, groin, and between toes, areas where growths hide.

Limit sun exposure for dogs with thin or white coats. Use pet-safe sun protection on exposed skin if your vet recommends it. Keep up with parasite prevention, since ticks and fleas cause skin irritation that can lead to secondary growths or infections. The World Small Animal Veterinary Association publishes dermatology resources that explain how skin health connects to overall care.

Monthly skin checks take five minutes. Do them after a bath or while your dog relaxes. Early detection is the single most useful habit you can build.

What Recovery and Ongoing Management Look Like

If your vet removes a benign skin tag, recovery is usually quick. Most dogs return to normal activity within a day or two. Stitches, if used, come out in 10 to 14 days. Keep the incision dry and prevent licking with an Elizabethan collar if your vet advises one. Mild swelling or redness for the first 48 hours is normal. Watch for oozing, a foul smell, or the incision opening, and call your vet if any of these appear.

If a biopsy shows a malignant tumor, the plan depends on the cancer type and stage. Surgery to remove the tumor with clean margins is common. Recovery may take two to three weeks. Your vet may recommend chemotherapy or radiation for certain cancers. Follow-up visits often happen every few months for the first year to check for recurrence. The MSD Veterinary Manual Pet Owner Version explains what to expect after surgical removal of skin masses.

For growths that are monitored without removal, check them monthly and photograph them. If a monitored growth changes, do not wait for the next scheduled visit. Call sooner.

Frequently Asked Questions

Can I put a bandage or ointment on my dog's skin tag? No. Bandages trap moisture and can cause the skin to break down. Ointments meant for humans often contain ingredients that are unsafe for dogs if licked. Leave the growth dry and clean. If it is bleeding or irritated, cover it lightly with a clean gauze pad for the trip to the vet, but do not apply any product. Your vet can recommend a safe cleanser if one is needed.

Will a skin tag fall off on its own? Rarely. True skin tags are stable growths that persist for months or years. If a growth falls off, it may have been a tick, a scab, or a growth that twisted and lost its blood supply. A growth that falls off still warrants a vet check, because the base tissue needs evaluation and the cause needs confirmation.

How much does skin tag removal cost? Costs vary widely by region and clinic. A simple removal during an exam might cost less than a surgical removal with biopsy. General ranges are helpful only as context. Ask your vet for a written estimate before the procedure. Many clinics offer itemized quotes that include anesthesia, pathology, and follow-up care.

My dog has many skin tags. Is that normal? Some dogs develop multiple benign skin tags as they age, especially in areas where skin rubs against skin or collars. However, multiple growths can also indicate an underlying condition such as a hormonal imbalance. Have your vet examine all of them at least once. After that, monitor each growth individually and report any that change.

Can a skin tag turn into cancer? A true skin tag is benign and does not transform into a malignant tumor. The concern is that a growth resembling a skin tag may actually be a different type of tumor from the start. This is why a biopsy is the only way to be certain. If your vet recommends testing, it is because the growth has features that need confirmation.

How long does a biopsy result take? Most pathology results come back within three to seven days. Some specialty labs offer faster turnaround for urgent cases. Your vet will call you with the results and explain what they mean. If the result is malignant, your vet will discuss next steps, which may include additional imaging or a referral to a veterinary oncologist.

Related Clinical & Scientific Guides

• Dog Ear Infection with Discharge: What the Color Tells You
• Cat Prednisolone for Allergies: Side Effects and Safe Use
• Dog Hair Loss on Nose: Causes and When to Worry

References and Further Reading

• WSAVA Global Dermatology Resources
• AVMA Pet Owner Resources
• MSD Veterinary Manual Pet Owner Version
• AAHA Pet Owner Resources

Related Articles

• Dog Ear Infection with Pain: How to Tell and What to Do
• Is My Dog's Skin Rash an Emergency? How to Tell
• Dog Skin Rash from Flea Collar: What to Do
• Dog Skin Rash with Odor: What It Means and What to Do
• Dog Itchy Skin Supplements: Do They Work?

This article is general educational information for pet owners. It is not a substitute for veterinary diagnosis, examination, or treatment. If your pet is showing severe or rapidly worsening signs, contact an emergency veterinary hospital immediately.