Dog lumps – when should I see a vet?

Updated 2026-09-30 · 1 sources

Based on: PDSA

Contact a vet today

This can have a serious cause – contact your vet today if any of the warning signs below apply, or if you are unsure. Lumps are common in dogs, and most aren’t cancerous.

When to contact a vetWhat to do now

Contact a vet if you see any of this

  • The lump is bothering your dog or affecting their mobility
  • The lump is getting bigger
  • The lump is becoming less movable
  • The lump is changing in appearance or texture
  • The lump is bleeding or weeping fluid

What you can do now

  1. Contact your vet.
  2. Note when it started, how often it happens and what else you see.
  3. Take a photo or short video to show the vet.
  4. Let your pet rest somewhere calm.
  5. Keep fresh water available.

Don't

  • Do not give any human medicine.
  • Do not wait if it gets worse.

What it can mean

A lump can be caused by an infection, wart, cyst, non-cancerous tumour or cancerous tumour.[1] Most lumps in dogs aren’t cancerous, but any new lump should be checked by your vet.[1] The location and appearance of a lump can give important clues, but most lumps need further testing.[1]

Possible causes

  • infections
  • warts
  • cysts
  • non-cancerous tumours
  • cancerous tumours

What the experts say

“Overview. Lumps are common in dogs. Most aren’t cancerous, but it's important to have any new ones checked by your vet. Causes: Lumps can be caused by variety of things such as infections, warts, cysts, non-cancerous tumours, and cancerous tumours.”

If your pet is struggling to breathe, has collapsed, is having a seizure or can't stand up: go to the nearest vet now.

Not sure how serious it is?

OkPaw asks a few quick questions about your pet and tells you in 30 seconds whether it can wait. Free on Google Play for Android.

Get it on Google Play

OkPaw is on Android now – an iPhone version is on its way.

Common questions

What can cause a lump in a dog?

A lump can be caused by an infection, wart, cyst, non-cancerous tumour or cancerous tumour.[1]

Do all dog lumps mean cancer?

Most lumps in dogs aren’t cancerous, but every new lump should be checked by a vet.[1]

What might the vet do?

The vet may examine the lump, and most lumps need further testing; one option is a fine needle aspirate, which takes a sample of cells using a small needle and syringe.[1]

Sources

  1. PDSA

How this page was made: written with the help of AI from the sources below, then checked claim by claim against those sources. Urgency levels follow OkPaw’s fixed safety rules. It is guidance, not a diagnosis. How we write our pages

The same page for cats →

Other symptoms in dogs

Mouth PainNystagmusOver-groomingRed or swollen eyesRed, inflamed or sore skinReduced AppetiteReverse SneezingRunny EyesScootingSeizuresSneezingSwollen Belly (Bloat)