What Should I Do If I Find a Lump on My Cat?

Not every lump is cancer, but every new lump needs checking. Here is what to note, what your vet may do and when to act.

Quick Answer

Not every lump is cancer, but there is no way of knowing what a lump is just by looking at it, so every new lump should be checked by a vet.
Lumps can have many causes, including abscesses, cysts, blood-filled swellings, ticks, insect bites, injection reactions, benign growths and cancer.
Take a photo, measure the lump with a ruler, note its shape and texture and whether it seems to hurt, then book a vet appointment.
Do not take a wait-and-see approach, because some lumps need immediate treatment, especially if they are infected.
Your vet may take a sample with a needle, take a biopsy or remove the lump, and a laboratory may then identify it.

Finding a lump can be worrying. If you are thinking "there is a lump on my cat", the first thing to know is that not all lumps are cancerous.

However, most lumps look similar from the outside. That is why the answer is always the same: contact your vet if you find a lump, even if it looks innocent.

This guide covers what a lump can be, what to note before you call, what your vet may do and when to act faster. It does not aim to help you decide what a lump is yourself.

Ginger long-haired cat with folded ears held gently by a person in a light apron - gentle handling is how many owners first notice a lump on their cat

What Could the Lump on My Cat Be?

Many different things cause lumps in cats. The descriptions below only show how wide the range is. Cats Protection says there is no way of knowing whether a lump is cancer just by looking at it.

An abscess

PDSA describes abscesses as pockets of pus that usually appear quickly and are extremely tender, often after a fight with another cat. Your vet may need to open and drain one.

See our guide on what to do if your cat has an abscess.

A cyst or a blood-filled swelling

PDSA describes cysts as harmless, fluid-filled pockets. Cats Protection says they are usually caused by blocked hair follicles or bacteria.

A haematoma is a blood-filled swelling. It is usually caused by an injury or surgery, or more rarely by a clotting problem.

A tick, insect bite or injection reaction

A fed tick is big enough to spot and feels like a small bump, often around the head, neck, ears and feet. Do not try to remove a tick by squeezing its body, because this can push blood back into your cat. Ask your vet if you are unsure. Our guide on what to do if your cat has a tick has more.

An insect bite or sting can make a cat swell up and go very red. A reaction to an injection, such as a vaccine, may swell a little, but contact your vet if the swelling persists.

Tabby and cream kitten held in the arm of a person wearing a white glove - a vet check is the way to find out what a lump on your cat is

Skin problems

Skin problems such as allergic skin disease can cause rashes, lumps and bumps. Cat chin acne starts with small dark specks or bumps on the chin and usually goes away on its own, but it may need treatment if it is persistent or severe.

Benign growths

Benign, or non-cancerous, tumours tend to be slow-growing and do not spread to the rest of the body. They cause problems if they get in the way, irritate or hurt, or become infected.

Lipomas, or fatty lumps, are one example. PDSA says they are uncommon in cats, while Cats Protection says they are more likely in older or overweight cats.

Cancerous lumps

Cancerous, or malignant, tumours can spread to other parts of the body. PDSA says they tend to grow quickly, but Blue Cross notes that cancers are often slow-growing. Generally, older cats are more often affected by cancer than younger cats, although young cats can be affected too.

Blue Cross says most lumps found in cats are benign, but that early action gives the best chance of recovery if a growth turns out to be cancerous. Cats with white or thin fur on the ears and head tend to be at higher risk of sun-related skin cancer.

What to Note About a Lump on My Cat

Take a photograph of the lump and measure it with a ruler. Then make a note of the following, because it helps your vet:

When you first found it, and how big it is.
Its shape, and its texture: smooth or knobbly, hard or soft.
Whether it seems to hurt or itch.
Whether it bleeds, weeps or has any discharge.
Any change in colour.

If your vet asks you to monitor the lump, they will advise how often to check it and what to record. PDSA offers a downloadable cat lump monitoring chart.

Tell your vet if the lump changes in size or texture, or starts to cause your cat pain. If the lump changes, book a check-up.

When to Contact Your Vet

You find any new lump, even if it looks innocent or your cat has had harmless lumps before.
The lump appeared quickly or is causing a problem.
A lump is growing (especially quickly), spreading or changing in shape, colour or texture, or it starts to bleed, discharge or cause pain.
A swelling is hot, very painful, burst or smelly, or your cat is unwell after a fight. It may be an abscess.
There is a sore or crusty patch that will not heal, especially around the ear tips, nose, eyelids or mouth.
A lump comes with a loss of appetite, weight loss, lethargy or difficulty breathing.
There is a lump on the nose, with nosebleeds, breathing difficulties or nasal discharge.

Book as soon as you can. Some lumps need immediate treatment, especially if they are infected, so do not take a wait-and-see approach. A new lump is usually not an emergency, but if your cat is struggling to breathe, has collapsed, or a lump is bleeding heavily, call your vet or the nearest out-of-hours emergency vet straight away.

How Your Vet Finds Out What a Lump Is

Because most lumps look similar from the outside, your vet may need to take a sample. This can be a fine needle aspirate, where a needle and syringe are used, a surgical biopsy, or removal of the whole lump. Some samples go to a laboratory.

Your cat may need sedation or an anaesthetic for sampling, and your vet may decide to remove the whole lump instead. A removed lump should go to a laboratory, which confirms what type it is and whether all of it was removed.

If cancer is suspected, blood tests, X-rays or an ultrasound scan can help show whether it has spread.

Treatment Depends on the Cause

Treatment can include medicine for an infected lump, draining, pain relief, a diet change if a food allergy is the cause, surgery, other cancer treatments, or simply monitoring. Some benign lumps need no treatment at all.

Many skin tumours are benign and can be surgically removed. Surgery is also the treatment used most often for cancer, and the one most likely to cure it, though complete removal is not always possible.

The outlook depends on the type of lump, where it is, how aggressive it is and whether it has spread. Some skin cancers can be cured if they are found and treated early.

What Not to Do

Do not assume a lump is harmless because it looks innocent. A new lump can turn out to be different from the last one.
Do not rely on how a lump looks or feels to decide whether it is cancer.
Do not use adult human sun cream on your cat. Ingredients such as zinc can be toxic to cats if licked.

Checking Your Cat Regularly

Run your hands over your cat's whole body from time to time. Grooming is a good chance to do this, so you are more likely to notice a new lump early.

Most cancers are not preventable, so regular check-ups and acting early are the best you can do. For cats at higher risk of sun-related skin cancer, such as light-coloured cats, you can reduce sun exposure by keeping them indoors when UV levels are high and providing shade. Ask your vet about pet-safe sun cream.

How Pet Med Direct Can Help

Regular grooming is a good time to check for lumps and bumps. Pet Med Direct supplies a cat grooming range.

A lump needs to be seen by your vet first. If your vet prescribes a medicine, you can find out how pet prescriptions work or browse our cat medication range.

Some pet medicines require a valid veterinary prescription. Pet Med Direct can only supply prescription medicines after the prescription has been checked. Always follow your vet's advice and the directions on the medicine label.

Frequently Asked Questions

Is a lump on my cat always cancer?

No. Many lumps are abscesses, cysts, bites or benign growths, but only a vet can tell which it is.

Should I wait to see if a lump on my cat goes away?

No. Book a vet appointment. Some lumps need immediate treatment, and delay could allow a cancer to spread.

How do I describe a lump on my cat to the vet?

Note when you found it, its size, shape and texture, whether it hurts, and whether it bleeds or weeps. Photograph it too.

Can I tell if a lump is serious by looking at it?

No. Most lumps look similar from the outside, and identifying them should be left to a vet.

Could the lump be a tick?

It could. A fed tick can feel like a small bump on the skin. Do not squeeze it, and ask your vet for advice if you are unsure.

Will my vet need to take a sample?

Possibly. Your vet may take a sample with a needle, take a biopsy or remove the whole lump, depending on what they find.

Related Cat Health Guides

Sources and Further Reading

This article was researched from the sources listed above. It is general information for cat owners and is not a substitute for advice from your own vet.

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This article is for informational purposes only and does not constitute veterinary advice.
If you are concerned about your cat’s health, please consult a qualified veterinarian.