Are lumps and bumps on cats and dogs normal?

Part of being a responsible pet parent is paying close attention to your dog or cat's body condition. Regular checks during grooming or petting time let you monitor their health in a low-stress way — for both of you.

A full, shiny coat and smooth, supple skin are signs of a healthy pet. If you notice a lump or bump during petting or grooming, don't panic — most are benign. That said, it's always a good idea to have any new lump checked by your vet.

Non-Cancerous Lumps on Dogs or Cats

Not all skin masses are life-threatening. Common causes of bumps under your pet's skin include:

• External parasites such as fleas and ticks
• Mites that burrow under the skin and can cause mange
• Environmental allergies from dust, mold, or pollen
• Food allergies from ingredients like beef, chicken, corn, or eggs
• Bacterial or yeast infections, often secondary to another condition
• Ringworm, a fungal infection affecting the outer skin and hair
• Hematomas (blood blisters)
• Cysts from clogged or inflamed glands
• Warts, small benign growths caused by a virus

Your vet will start with a physical exam and may ask how long the lump has been there, whether your pet seems bothered by it, and if you've noticed any behavior changes. They may also perform a Fine Needle Aspirate (inserting a needle to extract cells for microscopic evaluation) or a biopsy. Many non-cancerous lumps can be left alone or treated topically — surgical removal is only needed when necessary.

Tumors in Dogs and Cats

Benign Tumors

Tumors are abnormal tissue growths — and not all are cancerous. Benign tumors stay in one place and don't spread. A lipoma, for example, is a benign fat-cell tumor common in older dogs, especially females. While not life-threatening, they can grow large enough to interfere with movement and may require surgical removal.

Malignant Tumors

Malignant (cancerous) tumors grow and spread rapidly. Early detection is critical — if a mass looks suspicious, your vet may remove it immediately for testing and to determine the best treatment plan.

Lumps and Bumps on Older Dogs

Older dogs are especially prone to developing lumps as they age and have a higher risk of malignancies. If you have a senior dog, perform regular skin checks and schedule vet visits promptly when you find anything new. For more on caring for older dogs, see our guide on keeping senior dogs mentally active.

For general grooming and coat health tips that make regular checks easier, see our dog grooming collection and guide on how to give your dog a bath.