Dog Skin Bumps & Lumps — Types, Causes & When to Worry
Finding a new bump or lump on your dog can be alarming, but many are harmless. Dogs commonly develop lipomas, cysts, warts, and other benign growths. However, some lumps can be serious, so it's important to monitor them and know when veterinary evaluation is needed.
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Common Causes
Lipoma (Fatty Tumor)
Monitor at HomeSoft, moveable lumps under the skin composed of fat cells. Very common in middle-aged and older dogs. Usually benign and slow-growing. Often found on the trunk, legs, or armpits.
Sebaceous Cyst
Monitor at HomeRound, firm bumps that form when a hair follicle becomes blocked. May grow slowly and occasionally rupture, releasing thick, white material. Usually benign.
Warts (Papillomas)
Monitor at HomeCauliflower-like growths caused by papillomavirus. Common in puppies and dogs with weakened immune systems. Usually resolve on their own within a few months.
Histiocytoma
Monitor at HomeSmall, red, button-like growths common in young dogs under 3 years. Appear suddenly, often on the head, ears, or limbs. Usually regress on their own.
Allergic Reaction / Hives
Schedule Vet VisitMultiple raised bumps that appear suddenly, often after exposure to allergens like insect bites, plants, or medications. May be itchy and come with facial swelling.
Abscess
Schedule Vet VisitPainful, swollen lump filled with pus, usually from a bite wound or infection. The area is often warm, red, and tender. May rupture and drain.
Mast Cell Tumor
See Vet ImmediatelyThe most common malignant skin tumor in dogs. Can look like any other lump but may change size rapidly, be itchy, or cause surrounding redness. Requires biopsy.
Other Cancers
See Vet ImmediatelyVarious skin cancers including melanoma, squamous cell carcinoma, and fibrosarcoma. Warning signs include rapid growth, irregular shape, ulceration, or bleeding.
How to Photograph for Best AI Analysis
Getting a clear photo helps our AI provide more accurate insights. Follow these tips:
- Take a close-up photo showing the bump's size, shape, and color
- Include a reference for size (coin, ruler, or your finger)
- Photograph from multiple angles
- Show the location on your dog's body in a wider shot
- If the bump has changed, take photos over time to track changes
- Note if the area is hairless, red, or has any discharge
When to See a Veterinarian
Contact your veterinarian if you notice any of the following:
- •The lump is growing rapidly (doubling in size within weeks)
- •The bump is hard, immovable, or attached to underlying tissue
- •There's ulceration, bleeding, or discharge from the lump
- •The lump appeared suddenly and is painful or warm
- •Your dog is licking, scratching, or bothered by the lump
- •Multiple new lumps appear at once
- •The lump has an irregular shape or uneven borders
- •Any lump in an older dog that you haven't had checked
How PetSensAI Can Help
PetSensAI's skin scanner can help you document and track lumps and bumps on your dog. Our AI analyzes photos to identify characteristics that may indicate whether a lump needs urgent attention or can be monitored. Regular photo documentation helps track changes over time.
Related Symptoms
Sources
- VCA Animal Hospitals — Histiocytoma in Dogs
- VCA Animal Hospitals — Basal Cell Tumors in Dogs
About the Author
PetSensAI Editorial Team
Pet Health Content
Our editorial team creates pet health guides informed by reputable veterinary sources and reviewed for clarity and safety. Always consult a licensed veterinarian for medical advice.
Medical Disclaimer: This content is for informational purposes only and is not a substitute for professional veterinary advice, diagnosis, or treatment. Always consult a licensed veterinarian for any health concerns about your pet.
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Last updated: 2025-01-09