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Outbyte PC Repair FREEClear out junk files and repair common Windows errorsFree Scan →Outbyte Driver Updater FREEScan for outdated or missing drivers - takes under a minuteDriver Scan →Lymphoma in dogs is a cancer of lymphocytes, the white blood cells found in lymph nodes and other lymphoid tissue. The classic sign is one or more rapidly enlarging, painless lymph nodes, but the disease can also affect the gut, chest, skin, and other organs, so its signs vary widely. Only a veterinarian can confirm lymphoma, identify its subtype and stage, and recommend treatment. Most dogs with high-grade lymphoma are treated with systemic chemotherapy. That treatment often produces an initial response but seldom a cure, and the survival figures in circulation are group averages rather than forecasts for any one dog.
What are the signs of lymphoma in dogs?
The signs depend on where the lymphoma is. The most common form, multicentric lymphoma, accounts for about 80% to 85% of canine cases, according to the owner-facing entry of the Merck Veterinary Manual (updated September 2024).
Multicentric lymphoma
Multicentric disease usually shows up as lymph nodes that grow quickly and do not hurt. Owners most often notice enlargement under the jaw, at the front of the shoulders, or behind the knees. Nodes can grow to three to ten times their normal size. As the disease becomes more advanced or widespread, dogs may show lethargy, weakness, fever, loss of appetite, and dehydration.
Alimentary (gastrointestinal) lymphoma
Alimentary lymphoma makes up less than 10% of canine cases, per the same Merck owner-facing entry (updated September 2024). It can cause vomiting, abdominal discomfort, diarrhea, poor appetite, and weight loss. These signs overlap with many digestive problems, so persistent symptoms deserve a veterinary workup rather than a wait-and-see approach.
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Mediastinal lymphoma
Mediastinal lymphoma involves the tissue in the chest between the lungs and can cause breathing difficulty. Elevated blood calcium (hypercalcemia) can also occur. Merck reports that 10% to 40% of dogs with lymphoma may have hypercalcemia, and when calcium is high, a dog may drink and urinate more than usual.
Skin and other extranodal lymphoma
Skin lymphoma can appear as raised sores that heal slowly or as scaly areas. Lymphoma in other organs (extranodal disease) produces signs tied to the organ involved, which is why the veterinarian needs to know exactly where the disease is.
When to contact your veterinarian
- Any lymph node that is enlarging, particularly if more than one is affected.
- Vomiting, diarrhea, abdominal discomfort, or weight loss that persists.
- Lethargy, weakness, fever, loss of appetite, or dehydration.
- Raised or scaly skin changes, or sores that are slow to heal.
- Increased thirst and urination.
- Breathing difficulty. Acute breathing difficulty needs urgent veterinary care rather than a scheduled appointment.
None of these signs confirms lymphoma, because many conditions cause enlarged nodes and digestive upset. A home check cannot rule cancer in or out. The value of a prompt visit lies in the testing that follows.
How is lymphoma diagnosed?
An enlarged lymph node is a reason for an examination, not a diagnosis. Generalized, painless node enlargement is a common presentation, and the veterinarian must determine its cause. Merck describes the following sequence:
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1Repair Windows errors before they cause bigger problems2Fix the driver behind crashes, sound loss and screen glitches3Clear out junk files and repair common Windows errors- Clinical evaluation. The veterinarian examines the dog and palpates the lymph nodes and other body systems.
- Fine-needle aspiration (FNA) with cytology. A thin needle collects cells from a node or mass, and a pathologist examines them under a microscope. FNA can identify many cases.
- Tissue biopsy with histology. When FNA does not fully characterize the disease, a tissue sample is examined for its structure and cell appearance.
- Molecular and cell-surface testing. Flow cytometry characterizes cell surface markers, and PARR testing can help establish clonality, meaning whether the cells arise from a single expanding population, a pattern typical of cancer.
- Immunophenotyping. Histology and immunophenotyping can establish the morphological subtype, the grade, and whether the cells are B-cell or T-cell lymphocytes.
What are the stages of lymphoma in dogs?
Staging describes how far lymphoma has spread. The WHO scheme described in the Merck Veterinary Manual runs from limited nodal involvement to blood, marrow, or organ involvement. The stage number describes distribution, while the substage describes whether the dog has systemic signs.
| Stage | Distribution described by Merck |
|---|---|
| I | One lymph node, or lymphoid tissue in one organ (excluding bone marrow) |
| II | Multiple nodes in one regional area, with or without tonsils |
| III | Generalized lymph-node involvement |
| IV | Stage I to III with liver or spleen involvement |
| V | Stage I to IV with blood involvement and bone marrow or other organ-system involvement |
Substage a and substage b
Substage a means systemic signs are absent. Substage b means systemic signs are present. Merck’s table cites fever, weight loss greater than 10%, and hypercalcemia as examples of systemic signs.
The staging workup
NC State Veterinary Hospital describes a complete staging workup that may include:
- Complete blood count (CBC) with blood smear review
- Serum chemistry and urinalysis
- Chest radiographs and abdominal ultrasound
- Bone-marrow aspiration
- Phenotyping of the lymphoma cells
NC State states that staging is recommended because it can influence recommendations, help anticipate complications, and help predict prognosis. Which of these tests a particular dog needs is a case-specific decision for the veterinarian. The NC State page does not show a publication date, so its details should be checked against the clinic’s current practice. A stage on its own does not fully determine prognosis; subtype, grade, location, and response to treatment also matter.
How is lymphoma in dogs treated?
Treatment is planned around subtype, grade, location, extent of disease, the dog’s overall health, and the family’s goals. There is no single protocol that fits every case.
Systemic chemotherapy for high-grade lymphoma
For high-grade disease, Merck describes systemic chemotherapy. Common combination agents are part of CHOP-based protocols, which use cyclophosphamide, doxorubicin, vincristine, and prednisone. Protocols differ in drugs, schedule, and visit frequency.
Oral steroids
NC State lists oral steroids as one of its treatment options, alongside chemotherapy. Do not start, stop, or change prednisone or chemotherapy without your veterinarian, even if your dog seems well.
Other options
Radiation therapy, other agents, or, at select institutions, autologous bone marrow transplant may be considered in particular cases. Your veterinarian can advise whether referral to a veterinary oncology service would help.
Low-grade and site-specific disease
Low-grade lymphoma and lymphoma at different anatomical sites may call for different approaches than high-grade systemic disease.
Comparing options with your veterinarian
- Subtype and location, including B-cell or T-cell and high-grade or low-grade distinctions when tested.
- Disease extent and systemic signs, including stage and substage where established.
- Expected response, how long remission may last, and quality of life, not survival time alone.
- Visit frequency, how each treatment is given, side effects to monitor, and the family’s goals.
- Local cost and access.
NC State says treatment selection depends on goals, tolerance for visits, cost, and quality of life. Its page includes protocol schedules and cost estimates specific to that clinic. These are not universal current prices, so confirm schedules and costs directly with any clinic you are considering.
Independent reader supportYour contribution helps us test, update, and keep practical guides available for everyone.How long can a dog live with lymphoma?
Survival figures describe groups of dogs, not an individual dog. The table below lists each published figure with its source, date, and protocol. A median is not a countdown, and your veterinarian can interpret the diagnosis and response for your dog.
| Source and date | Group or treatment | Figure reported | Context |
|---|---|---|---|
| Merck Veterinary Manual, professional entry (updated April 2025) | B-cell lymphoma with systemic multidrug protocols | Median about 12 months | Group estimate |
| Merck Veterinary Manual, professional entry (updated April 2025) | T-cell lymphoma with systemic multidrug protocols | Median 6 to 8 months | Group estimate |
| NC State Veterinary Hospital, clinic page (no publication date shown; accessed 2026) | B-cell lymphoma with NC State’s standard protocol | Median 12 months | Clinic page estimate |
| NC State Veterinary Hospital, clinic page (no publication date shown; accessed 2026) | T-cell lymphoma with NC State’s standard protocol | Median 6 to 9 months | Clinic page estimate; slightly different from Merck’s T-cell range and not reconciled with it |
| Merck Veterinary Manual, professional entry (updated April 2025) | Conventional systemic chemotherapy | More than 90% initial response | Initial response estimate, not a cure rate |
| Merck Veterinary Manual, professional entry (updated April 2025) | No treatment | Death or euthanasia within 4 to 6 weeks | Individual courses vary |
| Merck Veterinary Manual, owner-facing entry (updated September 2024) | Low-grade lymphoma with chemotherapy | May survive longer than two years | A possible outcome, not a fixed duration |
What remission and relapse mean
Remission means a reduction or disappearance of detectable disease. It is not a guaranteed cure. Merck states that relapse is expected in most cases except some indolent forms, and that the disease may become refractory to continued treatment. Treatment can still improve quality of life and survival time.
Timothy M. Fan, DVM, PhD, DACVIM, author of the Merck Veterinary Manual professional entry, writes:
“Given that only a small fraction of dogs achieve a cure with conventional treatment options, the primary goal for treatment is palliative.”
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Questions to take to your veterinarian
- What subtype and immunophenotype (B-cell or T-cell) were found, and what grade is the lymphoma?
- What is the stage and substage, and does it change the plan?
- Which tests are useful for this dog, and what would each one change?
- What does each treatment aim to achieve: remission, control of disease, or comfort?
- Which side effects need a phone call, and how quickly should we call?
- How will response be monitored, and what would count as relapse?
- How do the visit schedule and cost fit our goals and budget?
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