Should you worry about lumps and skin tags on dogs?
A new lump on an older dog is the most common “is this serious?” call vets get. Most are benign fatty lumps called lipomas. The few that aren't, mast cell tumours and a handful of others, can look identical to the naked eye. The only honest way to know is a fine-needle aspirate at the vet, $80 to $200, results in 24 hours. Below: the 5-minute home check, what is benign vs concerning, and when to actually book the appointment.
The 5-minute home lump check
Once a month, on a settled dog, run your hands over the whole body in a slow systematic sweep. You are not feeling for tumours, you are feeling for changes from last month. Most owners catch new lumps that way long before a casual pat would notice.
- Start at the head and ears, work down the neck, behind the ears, under the chin.
- Move down each leg, including between the toes (a common spot for grass-seed cysts and mast cell tumours).
- Run flat palms across the body, down the back, along the flanks, across the chest and belly.
- Check the armpits and groin (often missed, often where lipomas hide).
- Lift the tail, check the back end and the area near the anus.
- Note size, shape, mobility, surface texture and any change since last month. A photo with a coin for scale is a useful record.
If you find something new and it has been there for less than a month, watch and wait isn't the right call. Anything new on a dog over 7 deserves a vet visit even if it feels soft.
The common types and what they look like
- Lipomas are soft, movable, slow-growing fatty lumps under the skin. About 50 per cent of dogs over 10 have at least one. Almost always benign.
- Sebaceous cysts feel like a pea-sized pearl under the skin, often on the back or shoulders. May discharge a thick paste. Benign but can become infected.
- Skin tags (acrochordons) are small dangling growths on a stalk. Common in older dogs. Benign unless catching on collars or licking.
- Histiocytomas are small, raised, often pink lumps in young dogs. Most resolve on their own in 1 to 3 months. Benign.
- Mast cell tumours are the impostors. Can look like any of the above. Soft, movable, sometimes change size hour to hour. About 10 to 20 per cent of skin lumps in dogs.
- Soft tissue sarcomas are firm, fixed, slow-growing. Often on a leg. Less common but locally invasive.
- Mammary tumours in undesexed female dogs. Around 50 per cent are malignant. The desexing guide covers the prevention argument.
When to worry, when to wait
Five flags that move a lump from “watch” to “vet within a fortnight”:
- Doubled in size in less than a month
- Hard, fixed to underlying tissue, doesn't move when you push it
- Ulcerated, bleeding, or scabbed over
- The dog is bothered by it (licking, scratching, painful to touch)
- Located on a face, paw, near a joint, or near the eye
Tell people when not to panic: a soft, movable, stable lump that has been there for 6 months on a healthy adult dog is almost always a lipoma. You don't need to remove it. You do need to check it monthly to confirm it stays stable.
Fine-needle aspirate, the cheap insurance
The fine-needle aspirate (FNA) is the test that ends the worry. A vet inserts a thin needle into the lump, draws out a few cells, smears them onto a slide, and either looks at them under their own microscope or sends them to a lab.
- Cost: $80 to $150 in-clinic, $150 to $250 if sent to an external lab for cytology review.
- Time: Same-day if read in-clinic, 24 to 72 hours via lab.
- Pain: Minor, similar to a vaccine. Most dogs barely react.
- Reliability: Roughly 90 per cent for distinguishing benign vs malignant. Some lumps need biopsy for a definitive answer.
If money is tight and you have multiple lumps to check, ask the vet to aspirate the largest and any new or changing ones. Watching the rest with photos for a few months is reasonable.
What removal costs in Australia
Most insurance covers diagnostics and removal if not pre-existing. The vet payment plans guide has options for non-insured cases.
Straight answers
How can I tell if a lump is dangerous?
You can't, reliably, with your hand. Soft and movable favours benign (lipoma); hard, fixed, fast-growing or ulcerated favours concerning. The only way to know is a fine-needle aspirate at the vet, $80 to $200, results in 24 hours.
How fast do dangerous lumps grow?
Mast cell tumours can double in weeks. Lipomas creep over months to years. The 'has it changed in the last month?' question is the most useful single screen. If yes, vet.
Should I have benign lipomas removed?
Usually no, unless they're in an awkward spot (armpit, between toes, near the eye) or growing into something. Removal is $400 to $1,500 under anaesthetic, and lipomas don't become cancerous. Cosmetic-only removal is hard to justify.
What's the difference between a mast cell tumour and a fatty lump?
On feel, often nothing. Both can be soft and movable. The histology under a microscope is what tells you. About 1 in 10 'soft lumps' that get aspirated turn out to be mast cell, which is exactly why vets aspirate them.
Are lumps more common in older dogs?
Yes, sharply. By age 10, around 50 per cent of dogs have at least one fatty lipoma. The cancer rate also climbs with age, particularly in Boxers, Golden Retrievers and Shar Pei breeds.
Can I just watch and wait on a small lump?
Watch and wait is reasonable for a lump that's been stable in size for 3+ months in a dog with no other lumps. Track it monthly, photograph it next to a coin for scale. Anything growing, that's a vet visit.
Most lumps on dogs are nothing. The job is to identify the few that are something, before they become harder to treat. The 5-minute monthly check plus an FNA on anything new costs you a few hundred dollars across a dog's life and turns up most cancers when they are still small. Related: emergency vet Sydney, find a vet, payment plans. Information here is general and isn't a substitute for veterinary advice.