What are the common symptoms of lymphoma in cats?

Common signs include lethargy, decreased appetite, weight loss, repeated vomiting or diarrhoea, and palpable lymph node enlargement. Consult your vet if symptoms persist or worsen.

How does a vet diagnose lymphoma in cats?

Diagnosis typically combines bloodwork, biochemistry, imaging (radiographs and ultrasound), and cytology or tissue biopsy. Immunophenotyping or PCR may also be used to assist with subtype classification. Your vet will determine which tests are appropriate.

What are the treatment options for feline lymphoma?

Treatment may include IV fluids and supportive care to manage symptoms. Tumour-targeting treatments such as chemotherapy require evaluation by a specialist who can discuss risks and prognosis. Shared decision-making with your vet is recommended.

What information should pet owners prepare before the vet visit?

It is helpful to record the onset date of symptoms, daily food intake and bowel movement logs, and to bring videos or photos, a current medication list, and any previous test reports to assist the vet in a quick assessment.

How much do the tests and treatment usually cost?

Costs vary by clinic and region — ask your vet for an estimate before proceeding.

Disease Guide

Cat Lymphoma: Complete Guide to Symptoms, Diagnosis & Care [2025]

Feline lymphoma is one of the most common cancers in cats, affecting the gastrointestinal tract, mediastinum, or multiple organs. Chemotherapy can help extend survival time.

Take 1 minute to check the symptoms first

Last updated: 2026/01/05

Pethealthmap Editorial Team

Sources: ISFM, ACVIM, National Taiwan University Veterinary Hospital

When to See a Vet

Seek emergency care immediately

•Rapid breathing or breathing difficulty with visible open-mouth breathing
•Sudden fainting or loss of consciousness with no response
•Repeated vomiting with obvious dehydration or bloody stools

Schedule a clinic visit soon (within 24–72 hours)

•Noticeably reduced appetite with rapid weight loss
•Clearly lethargic and unwilling to move for more than two days
•Repeated diarrhea or vomiting affecting food intake and persisting for more than one day

01What symptoms indicate something is wrong?

Lymphoma in cats often manifests as visible or systemic changes, commonly involving energy levels, appetite, gastrointestinal function, and body weight.

Persistent lethargy and noticeably reduced activity
Significant decrease in appetite or complete refusal to eat
Repeated vomiting, nausea, or discomfort after eating
Diarrhoea or changes in bowel habits (frequency or consistency)
Rapid and sustained weight loss over a short period
Unexplained fever or persistent low-grade fever

Seek emergency care immediately if you notice the following symptoms:

⚠️ Severe breathing difficulty or rapid, laboured breathing
⚠️ Sudden collapse or loss of consciousness — seek emergency care immediately
⚠️ Repeated vomiting causing obvious dehydration or bloody stools

02How to assess changes at home: what to observe and when to go to emergency care

Observations and notes you can make at home help your vet understand the progression of illness and make faster decisions.

Note when changes in energy and activity first appeared and how long they have lasted
Record daily food intake, whether your cat eats willingly, and meal times
Log the number of vomiting episodes, contents (bile, food, or blood), and times of occurrence
Observe and record stool consistency, colour, and the presence of blood or mucus
Weigh your cat weekly and track weight trends for comparison
Film short videos on your phone of relevant behaviours (eating, walking, vomiting) to share with your vet
If symptoms worsen or warning signs appear, arrange a vet visit immediately

03How does the vet make a diagnosis? Common diagnostic tests

At the clinic, the vet will combine a physical examination with imaging and laboratory tests, and may arrange further pathological or molecular testing if needed.

Complete blood count and biochemistry panel

to assess blood cells and organ function including the liver and kidneys

Urinalysis

to rule out kidney or urinary tract conditions

Thoracic and abdominal radiographs

to check for changes in thoracic or abdominal organs

Abdominal ultrasound

to evaluate lymph node enlargement or organ involvement

Cytology or tissue biopsy

pathological examination to confirm cell type

PCR or immunophenotyping

to assist with classification and prognostic assessment

Referral to a hospital with oncology or advanced diagnostic capability is recommended

04How to treat and care for your cat after diagnosis: medications, diet, and care guide

Treatment and monitoring plans are tailored to each individual case, encompassing symptom relief, tumour control, and quality of life support.

Short-term IV fluids and anti-nausea medication to relieve dehydration and acute discomfort
Chemotherapy or other oncology treatments require evaluation and guidance from a specialist vet
Adjust the diet to provide high-calorie, high-protein nutritional support
Schedule regular follow-up blood tests and imaging to monitor treatment response and side effects
Record and report any medication side effects to the veterinary team
Discuss a long-term monitoring and home care plan with the specialist hospital

05What to prepare before seeing the vet: key information to help your vet assess quickly

Note the onset date of symptoms and daily changes (written notes or photos)

Prepare recent records of food intake, vomiting, and bowel movements (times, frequency, and content)

List all current medications, supplements, and vaccination records

Bring videos or photos to help illustrate symptoms and behavioural changes

Bring copies of any previous test results or imaging for comparison

Use a secure, appropriately sized carrier, and book a specialist or general consultation in advance

This content is for reference only and cannot replace a professional veterinary diagnosis. If your pet shows signs of illness, please seek veterinary care promptly.