Get

In Your Inbox

Catster is reader-supported. When you buy via links on our site, we may earn an affiliate commission at no cost to you. Learn more.

What Causes Lumps on Cats? 6 Possible Causes & What to Do

kitten with lump on skin

Imagine petting your cat and feeling something that doesn’t feel quite right. Is that a lump? Immediate concern and panic set in. As you pick up the phone to call your veterinarian, your mind is likely racing as to what this lump could possibly be. Continue reading below to learn more about six of the most common causes of lumps in cats.

divider 2 cats

The 6 Common Causes of Lumps on Cats:

1. Insect Bites

Fleas, ticks, and other insects can potentially bite or sting your companion, which can result in a lump or bump. Flea bites often cause several small bumps referred to as miliary dermatitis throughout their body, with a focus around the neck and tail base.

A single bump or localized swelling is more often found with other types of bites. In some cases, a palpable bump may actually be an attached tick. Appropriate preventative measures can help reduce the risk of parasitism.

If you need to speak with a vet but can't get to one, head over to PangoVet. It's an online service where you can talk to a vet online and get the advice you need for your pet — all at an affordable price!

PangoVet_Mention-in-Content for PangoVet2 save money


2. Cancer

Unfortunately, some lumps that develop on your cat can be cancerous. Malignant growths can metastasize and cause problems elsewhere in the body. Depending on the type of growth present, surgical removal may be recommended. In cases where surgical removal is not an option, radiation may be beneficial.

Historically, a common cancer that cats developed was coined injection site sarcoma. This type of cancer was often associated with an inflammatory reaction that occurred secondary to vaccine adjuvants. Nowadays, this type of cancer is less common, as non-adjuvanted vaccinations have been developed and utilized.

cat being observed by a female veterinarian
Image Credit: David Herraez Calzada, Shutterstock

3. Benign Growths

Some growths that develop can be benign, or non-cancerous. A well-known type of benign growth is a lipoma or fat. Other types of growths can occur as well that do not impact other parts of the body and do not spread.


4. Abscess

When an infection occurs and is walled off within the body, an abscess is formed. Abscesses can form an obvious lump consisting of pus, which is often warm and painful to the touch. Abscess can form for a variety of reasons; however, one of the most common reasons is from fighting with other cats.

Abscess may need to be surgically addressed, whereas others may improve with antibiotics and pain medication. Animals with abscesses can often appear systemically ill, showing signs of lethargy, fever, and decreased appetite.

abscess on cat's neck
Image Credit: Elena11, Shutterstock

5. Inflammation

Injury or trauma can cause inflammation to occur that can palpate as a bump. Depending on the underlying cause of inflammation, your veterinarian will formulate a plan to help bring relief to your pet.


6. Lymph Node Enlargement

Lymph nodes are an important part of the immune system, as they house white blood cells that respond to infections. Lymph nodes can become enlarged because of a nearby infection, whereas other times they can be enlarged due to cancer. There are places where lymph nodes are readily palpable on the body, including under the chin, near the clavicle, and behind the knees.

vet checking up a cat with the owner
Image Credit: Stock-Asso, Shutterstock

divider 1 paws

Diagnosing a Lump

When you find a bump on your cat, the first step in understanding the cause is to schedule an appointment with your veterinarian. Your veterinarian will listen to your concerns, inquire about your cat’s history, and perform a thorough physical exam. Based on their findings and suspicions, recommendations will be given to provide the best care for your pet.

When a lump is found, especially if an underlying cause like parasites or trauma isn’t identified, a fine needle aspirate may be recommended. Obtaining a fine needle aspirate is achieved by introducing a needle connected to a syringe into a mass and pulling out a sample of cells. The cells are then placed on a slide and evaluated under the microscope. The cells are closely studied, and a diagnosis is made.

Sometimes, a diagnosis may not be definitive, and additional testing may be necessary. Additional testing may include a tissue biopsy, bloodwork, or ultrasound.

female vet checking up the cat
Image Credit: Ermolaev Alexander, Shutterstock

Treatment

Treatment for lumps and bumps on your cat will be dependent on the underlying diagnosis. Infections like abscesses will require antibiotics, whereas cancerous growths will likely require removal and possibly additional care. Close collaboration with your veterinarian is critical!

It is important to keep your veterinarian up to date with your pet’s progress. If things are not improving in the way that is anticipated, it is possible a different approach is necessary.

divider 2 cats

Conclusion

Cats can develop lumps and bumps for a variety of reasons. If a new bump suddenly arises or if your pet seems to be in discomfort, it is important to schedule a consultation with your vet. Your veterinarian will perform a physical examination to help determine the underlying cause and discuss treatment options.

See also:


Featured Image Credit: Mironmax Studio, Shutterstock

Want content like this delivered to you?

Sign Up For Our Newsletter

News, insights, expert advice, and everything cat

* By submitting, you agree to our Terms & Conditions and Privacy & Cookies Policy.

How useful was this post?

Click on a star to rate (you can leave written feedback after clicking submit)

Help us improve Catster for pet parents!

Your feedback really matters.

What did you like about this post? Also how can we improve it?

Join the conversation

Leave a Reply

You’re very welcome to leave a comment or question. Please know that all comments must meet our community guidelines, and your email address will NOT be published. Let’s have a positive and constructive conversation.

Talk With A Vet Online

Peace of mind,
anywhere, anytime

Affordable vet advice

My Cat’s Fur is Changing Color: 6 Vet Approved Reasons for Coat Changes

Going gray as you age is a fact of life, and we either accept it or do something about it. Sometimes, we also...

Kucing Malaysia: Breed Info, Pictures, Care & Characteristics

The Kucing Malaysia is a relatively new breed of cat, having only been first bred in the 1990s. It is the first Malaysian...

Can My Cat Understand Dogs or My Other Cat? Animal Communication Explained

If you’ve spent any time online watching cute animal videos, you’ve probably come across at least one highlighting the relationship between an unlikely...

How Much Water Does a Cat Need per Day? Vet-Approved Facts & Health Tips

Like humans, cats require access to fresh drinking water, which is essential for proper body functioning and optimum health. Water helps cats maintain...

More related

Could My Cat’s Swollen Face Be Cancer? Tumors, Cysts, & Lumps Explained (Vet Answer)

It can be pretty scary if your cat develops facial swelling, regardless of whether it is sudden. The first thing that comes to...

8 Common Litter Box Issues & How to Fix Them

It’s a common myth that cats always use their litter boxes without issue. For the most part, cats indeed learn to use a...

Do Cats Miss You When You’re Gone? Vet-Reviewed Facts on Feline Behavior

While cats are often judged as aloof and even indifferent, a 2019 study by the Department of Animal and Rangeland Sciences (Oregon State...

How To Litter Train An Older Cat: 12 Vet-Approved Steps

If you have an older outdoor cat who needs to start living inside, you may be wondering if it’s possible to train them...

Keep reading

7 Best Glucose Meters for Cats in 2026 – Reviews & Top Picks

It can be stressful learning that your cat has diabetes, and the thought of poking them with a needle to draw blood can seem overwhelming. The last thing you want is for your cat to be ill, and as a...

Cat's owner measuring the blood sugar values of his feline using glucometer

How to Introduce a Puppy to Cats (10 Vet-Verified Tips)

If you already have a cat at home but are considering adopting a puppy, you might be wondering if there are any steps you can take to minimize stress for all parties involved. Cats often don’t react well to changes...

a cat and a puppy outside

Can Cats Eat Muffins? Vet-Reviewed Risks & Safe Alternatives

Many of us enjoy munching on a muffin from time to time. They are tasty and can fill the gap when you’re hungry between mealtimes. There are so many options, too—blueberry, chocolate, bran, and cranberry, just to name a few!...

Can Cats Eat Muffins

How Does a Cat Purr? The Evolution & Meaning Behind a Purr (Vet Reviewed)

Cats are known for their adorable vocalizations, and their purring is usually a sign of contentment and happiness. But have you ever wondered how your cat makes that calming vibration? Cats purr by vibrating their laryngeal muscles through several mechanisms....

cat purring

Can Cats Eat Celery? Vet-Reviewed Nutrition Facts & FAQ

Celery is a popular chips-and-dip accompaniment, and while your cat definitely shouldn’t have the chips or the dip, what about the celery itself? Can cats eat celery? In fact, there’s nothing wrong with giving them a few celery stalk pieces...

Can Cats Eat Celery

Do Cats Like Eucalyptus Scent? What You Should Know!

Cats have an acute sense of smell that they rely on for communication and gathering information about their surroundings. It’s no secret that cats are biased toward some smells, like their food and the rotisserie chicken that’s about to be...

eucalyptus

Cat Ear Mites vs Earwax: Vet-Reviewed Ways to Tell the Difference

Earwax is entirely normal. Ear mites, on the other hand—not so much. If your cat has ear mites, they will require veterinary care. While ear mites aren’t often serious, they can cause extreme itching, discomfort, and even skin lesions if...

cat ear mites vs cat earwax featured image

How Cold Is Too Cold for Cats? Vet-Reviewed Facts & FAQ

It’s easy to overestimate a cat’s tolerance for the cold. When they walk around sporting several inches of insulating fluff and act nonchalant in frigid outdoor weather, who can blame you? The outdoors is what many cats call home, and...

Neva Masquerade cat in the snow