18 May 2026

Lymphoma in Dogs and Cats: Signs, Staging, and Treatment

MaxPetz 8 min read
Lymphoma in Dogs and Cats: Signs, Staging, and Treatment

What are the first signs of lymphoma in dogs and cats?

Lymphoma is a cancer of the lymphatic system affecting both dogs and cats. The most common early sign in dogs is painless swelling of the lymph nodes, particularly under the jaw, in front of the shoulders, or behind the knees. Cats more often show internal signs such as weight loss, vomiting, and reduced appetite before any visible swelling appears.

MaxPetz in Delhi provides dedicated cancer care for pets, including diagnostic workup and treatment planning for canine and feline lymphoma.

  • Enlarged, firm, non-painful lymph nodes (dogs)
  • Unexplained weight loss
  • Reduced appetite or refusal to eat
  • Lethargy and reduced activity
  • Increased thirst and urination
  • Vomiting or diarrhoea (more common in cats)
  • Difficulty breathing or swallowing (if chest nodes are involved)
  • Skin lesions or patches (cutaneous lymphoma)

Note: Lymph node swelling in dogs can also be caused by infection or other conditions. A veterinary examination is essential to distinguish lymphoma from other causes.

What symptoms appear in the final stages of canine lymphoma?

As lymphoma progresses, symptoms become more pronounced and systemic. Late-stage or stage 4 and stage 5 lymphoma in dogs involves spread to the bone marrow, liver, spleen, or other organs, producing a distinct set of clinical signs.

StageWhat It MeansCommon Signs
Stage 1Single lymph node region affectedLocalised swelling, often no other signs
Stage 2Multiple nodes, one side of diaphragmVisible node enlargement, mild lethargy
Stage 3Generalised lymph node involvementWeight loss, reduced appetite, fatigue
Stage 4Liver and/or spleen involvedAbdominal swelling, vomiting, jaundice
Stage 5Bone marrow or blood involvementAnaemia, bleeding, severe weakness, collapse

In the final stages, dogs may also show difficulty breathing, persistent vomiting, and complete loss of appetite. Palliative care focuses on maintaining comfort and quality of life at this point.

How is lymphoma diagnosed in dogs and cats?

Accurate diagnosis is essential before any treatment is started. Several conditions — including infections, immune-mediated disease, and other cancers — can mimic lymphoma. A thorough diagnostic workup at MaxPetz Delhi helps confirm the diagnosis and determine the subtype, which directly influences treatment choice.

What can be mistaken for lymphoma in dogs? Conditions such as tick-borne infections (e.g. ehrlichiosis), fungal infections, and reactive lymphadenopathy (node swelling due to infection) can all cause enlarged lymph nodes and similar symptoms. This is why laboratory confirmation is required before a lymphoma diagnosis is made.

Typical diagnostic steps include:

  1. Fine-needle aspirate (FNA) — a minimally invasive sample taken from an enlarged lymph node, examined under a microscope
  2. Biopsy — a tissue sample for histopathology, which confirms the lymphoma subtype (e.g. B-cell vs. T-cell)
  3. Blood tests and urinalysis — to assess organ function and detect anaemia or abnormal cell counts
  4. Imaging (X-ray / ultrasound) — to evaluate internal organ involvement and stage the disease
  5. Bone marrow aspirate — if stage 5 disease is suspected

Warning: Do not start corticosteroids (such as prednisolone) before a confirmed diagnosis. Steroids can temporarily shrink lymph nodes and mask the disease, making subsequent diagnosis and chemotherapy less effective.

What does lymphoma treatment involve for dogs and cats?

Treatment for lymphoma in pets depends on the species, lymphoma subtype, stage, and the pet's overall health. The goal of treatment is to achieve remission — a state where cancer signs are no longer detectable — and to maintain quality of life for as long as possible.

Treatment options for canine lymphoma:

  • Multi-agent chemotherapy (CHOP protocol) — the most effective approach for most dogs with multicentric lymphoma; involves a combination of drugs given over several weeks
  • Single-agent chemotherapy — using drugs such as doxorubicin or lomustine; used when multi-agent protocols are not feasible
  • Corticosteroids alone — a palliative option that may temporarily reduce node size and improve comfort, but does not achieve true remission
  • Radiation therapy — used for localised forms such as nasal or cutaneous lymphoma

Treatment options for feline lymphoma:

  • Cats with low-grade (small cell) gastrointestinal lymphoma often respond well to oral chlorambucil and prednisolone, with a good quality of life maintained for extended periods
  • High-grade feline lymphoma is treated with multi-agent chemotherapy, though response rates and survival times are generally shorter than in dogs

For both species, supportive care — including anti-nausea medication, appetite stimulants, and nutritional support — is an important part of the treatment plan. Use the booking form on this page to discuss a tailored treatment plan with the cancer care team at MaxPetz Delhi.

What is the life expectancy of a dog with lymphoma?

Prognosis varies considerably depending on the lymphoma subtype, stage at diagnosis, and whether treatment is pursued. Understanding realistic expectations helps pet owners make informed decisions about care.

ScenarioTypical Outcome
Dog, B-cell, CHOP chemotherapyRemission in the majority of cases; median survival around 12 months
Dog, T-cell lymphoma, chemotherapyGenerally shorter remission and survival than B-cell disease
Dog, corticosteroids onlyMedian survival 1–3 months; palliative intent
Dog, untreatedMedian survival 4–6 weeks from diagnosis
Cat, low-grade GI lymphoma, oral chemoMany cats maintain good quality of life for 2 or more years
Cat, high-grade lymphoma, chemotherapyRemission possible; median survival typically shorter than low-grade

Can lymphoma in dogs go into remission? Yes. With appropriate chemotherapy, many dogs with B-cell multicentric lymphoma achieve complete remission. However, most dogs eventually relapse; second-line protocols can sometimes achieve a second remission.

What is the average age dogs get lymphoma? Lymphoma can occur at any age but is most commonly diagnosed in middle-aged to older dogs, typically between 6 and 9 years of age. Certain breeds — including Golden Retrievers, Boxers, and Bulldogs — appear to be at higher risk.

When should you bring your pet to a vet for lymphoma assessment?

Early veterinary assessment improves the chances of achieving remission and maintaining quality of life. Do not wait to see if symptoms resolve on their own.

Consult a vet promptly if your dog or cat shows any of the following:

  • A lump or swelling under the jaw, in the neck, armpit, or groin that has been present for more than 1 week
  • Unexplained weight loss of more than 10% of body weight over 4 weeks
  • Persistent reduced appetite lasting more than 3 days
  • Lethargy that does not improve with rest over 48 hours
  • Vomiting or diarrhoea occurring more than twice in a 24-hour period
  • Difficulty breathing, swallowing, or any visible facial swelling
  • Increased thirst and urination alongside any of the above

If your pet has already been diagnosed with lymphoma and develops sudden collapse, laboured breathing, or uncontrolled bleeding, seek emergency veterinary care immediately.

The cancer care team at MaxPetz Delhi can assess your pet, confirm a diagnosis, and outline the most appropriate management pathway. Use the booking form on this page to arrange an appointment.

How does MaxPetz Delhi approach pet cancer care?

MaxPetz in Delhi offers veterinary cancer care that combines clinical rigour with compassionate support for both pets and their owners. The team uses cutting-edge diagnostic technology to accurately stage lymphoma and other cancers, enabling treatment plans that are tailored to each individual patient's subtype, stage, and overall health status.

  • Structured diagnostic workup including cytology, histopathology, and imaging
  • Chemotherapy protocols adapted to the pet's species, subtype, and clinical condition
  • Integrated supportive care to manage treatment side effects and maintain quality of life
  • Clear, honest communication with pet owners about prognosis and options at every stage

Whether you are seeking a first opinion on a newly discovered lump or a second opinion on an existing diagnosis, the cancer care specialists at MaxPetz Delhi are available to help. Use the booking form on this page to get started.

Book a cancer care consultation at MaxPetz Delhi

Use the booking form on this page to arrange an assessment for your pet.

FAQs

  • The most common first sign of lymphoma in dogs is painless enlargement of the lymph nodes, most noticeable under the jaw, in front of the shoulders, or behind the knees. Other early signs include mild lethargy, reduced appetite, and unexplained weight loss. Many dogs appear otherwise well in the early stages, which is why any persistent lump should be assessed promptly.
  • Diagnosis typically begins with a fine-needle aspirate of an enlarged lymph node, which is examined under a microscope. A tissue biopsy is often needed to confirm the subtype. Blood tests, urinalysis, and imaging (X-ray or ultrasound) are used to assess organ involvement and stage the disease. Accurate diagnosis is essential before treatment begins, as other conditions can mimic lymphoma.
  • Life expectancy depends on the lymphoma subtype and treatment chosen. Dogs with B-cell lymphoma treated with multi-agent chemotherapy (CHOP protocol) commonly achieve remission, with a median survival around 12 months. Dogs receiving corticosteroids alone typically survive 1–3 months. Without treatment, median survival is approximately 4–6 weeks. A veterinary oncology assessment helps set realistic expectations for each individual case.
  • Yes. Feline lymphoma is treatable, and outcomes depend heavily on the subtype. Cats with low-grade gastrointestinal lymphoma often respond well to oral chemotherapy and can maintain a good quality of life for two or more years. High-grade lymphoma is more aggressive, but remission is still achievable with chemotherapy. Early diagnosis and accurate subtyping are key to selecting the most effective treatment.
  • Yes. Many dogs with B-cell multicentric lymphoma achieve complete remission with multi-agent chemotherapy. Remission means that signs of cancer are no longer detectable, though it does not mean the cancer is permanently eliminated. Most dogs eventually relapse, but second-line chemotherapy protocols can sometimes achieve a second remission. T-cell lymphoma generally has shorter remission times than B-cell disease.
  • Several conditions can cause enlarged lymph nodes and mimic lymphoma, including tick-borne infections such as ehrlichiosis, fungal infections, and reactive lymphadenopathy caused by localised infection or inflammation. Immune-mediated diseases and other cancers can also present similarly. This is why laboratory confirmation — through cytology or biopsy — is essential before a lymphoma diagnosis is made and treatment is started.

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