Lymphoma in cats – signs and when to see a vet

Updated 2026-09-30 · 2 sources

Based on: PDSA, International Cat Care (iCatCare)

Contact a vet today

Contact your vet today if you think your cat has this – it can become serious. Lymphoma is a cancer of lymphocytes, also known as white blood cells.

What to do now

What you can do now

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

Don't

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

What it is

Lymphoma is a cancer of lymphocytes, also known as white blood cells.^[1] In cats, lymphoma can be found in places including the intestines, chest, kidneys, skin and lymph nodes.^[1]

Signs

Vomiting
Diarrhoea
Weight loss
Reduced appetite
Lethargy or tiredness
Difficulty breathing, including faster breathing or panting
Coughing
Increased thirst
Increased urination
Lumps under the jaw or elsewhere on the body

Causes and risk factors

Oriental breeds
Siamese cats, especially males
A lowered immune system
Genetic predisposition
Environmental toxins, such as cigarette smoke

How a vet finds out

Blood tests
X-rays
An ultrasound scan
Samples from local lymph nodes or glands
A sample of tissue from a lump

How vets treat it

Chemotherapy drugs may be used in an attempt to slow cancer growth and shrink tumours. The aim is to improve quality of life and achieve remission.

Breeds prone to this

Veterinary charities list these breeds as more likely than others to get this condition. Each breed page lists the inherited conditions documented in the breed.

What the experts say

“To confirm a diagnosis, decide on the best treatment plan, and to give a prognosis, your vet will advise doing certain tests to grade and stage your cat’s lymphoma: Grading - tells us how aggressive the lymphoma is by taking a sample of tissue from the lump.”
— PDSA [1]

“Before starting treatment, your vet may ‘stage’ the lymphoma. This is done through x-rays/ultrasounds, taking samples from local lymph nodes (glands) and blood tests, to find out how far the lymphoma has spread and what (if any) complications have arisen.”
— International Cat Care (iCatCare) [2]

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.

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

Common questions

What is lymphoma in cats?

Lymphoma is a cancer of lymphocytes, also known as white blood cells.^[1]

What signs can lymphoma cause?

Signs can include vomiting, diarrhoea, weight loss, reduced appetite, tiredness, difficulty breathing, coughing, increased thirst or urination, nose discharge or bleeding, and lumps under the jaw or elsewhere on the body.

How might a vet treat lymphoma?

Chemotherapy drugs may be used in an attempt to slow cancer growth and shrink tumours; the aim is to improve quality of life and achieve remission.^[1]

Sources

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 dogs →