What are the symptoms of lymphoma in dogs?

The most common sign is painless swollen lymph nodes — especially under the jaw, in front of the shoulders, and behind the knees. Other symptoms include lethargy, weight loss, decreased appetite, increased thirst and urination, vomiting, diarrhea, and difficulty breathing. Many dogs with early lymphoma feel well despite the diagnosis.

What does bloodwork show in a dog with lymphoma?

Bloodwork changes vary. CBC may show anemia, thrombocytopenia (low platelets), and sometimes circulating abnormal lymphocytes. Chemistry may reveal elevated calcium (hypercalcemia in 10–40% of dogs with T-cell lymphoma), elevated liver enzymes if the liver is involved, and low albumin. LDH (lactate dehydrogenase) may be elevated. Normal bloodwork does not rule out lymphoma.

What is the CHOP chemotherapy protocol for dogs?

CHOP is the standard multi-drug chemotherapy protocol for canine lymphoma. It combines Cyclophosphamide, Hydroxydaunorubicin (doxorubicin), Oncovin (vincristine), and Prednisone over approximately 19–25 weeks. It achieves remission in 70–90% of dogs with B-cell lymphoma. CBC is checked before every treatment to ensure adequate white blood cell and platelet counts.

What is the prognosis for a dog with lymphoma?

With CHOP chemotherapy, median survival for B-cell lymphoma is 12–14 months, with about 25% of dogs surviving 2 years. T-cell lymphoma has a worse prognosis: median 6–9 months. Without treatment, most dogs survive 4–6 weeks. Dogs tolerate chemotherapy well compared to humans — most maintain a good quality of life throughout treatment.

What is the difference between B-cell and T-cell lymphoma in dogs?

B-cell lymphoma (80% of cases) generally has a better prognosis — median survival 12–14 months with CHOP. T-cell lymphoma (20%) is more aggressive — median survival 6–9 months. T-cell is also associated with hypercalcemia. Immunophenotyping (flow cytometry or immunohistochemistry) determines cell type and is now considered standard of care before starting treatment.

How is dog lymphoma diagnosed?

Fine needle aspirate (FNA) of an enlarged lymph node is the first step — a quick, minimally invasive procedure. Cytology from the aspirate can confirm lymphoma. For definitive diagnosis and immunophenotyping, a lymph node biopsy is more informative. Flow cytometry or PCR for antigen receptor rearrangement (PARR) determines B-cell vs T-cell type.

How often is bloodwork needed during lymphoma treatment?

CBC is checked before every chemotherapy treatment — typically weekly or every 3 weeks depending on the protocol. If neutrophils are too low (neutropenia), treatment is delayed. Chemistry panels are checked periodically throughout treatment to monitor liver and kidney function. Owners who upload these results to a tracking tool can see trends across the full treatment course.

Lymphoma in Dogs: Symptoms, Stages, Treatment & Bloodwork

Q: What is lymphoma in dogs?

Lymphoma is a cancer of lymphocytes — white blood cells that are part of the immune system. It's one of the most common cancers in dogs, accounting for 15–20% of all canine tumors. It can arise in lymph nodes, the spleen, liver, bone marrow, skin, or gastrointestinal tract. The most common form (multicentric) causes enlarged lymph nodes throughout the body.

Quick Answer: Lymphoma in Dogs

Lymphoma is one of the most common cancers in dogs, accounting for 15–20% of all canine tumors. With CHOP chemotherapy, 70–90% of dogs achieve remission and median survival for B-cell lymphoma is 12–14 months. Dogs undergoing chemo receive CBC checks before every treatment — making this one of the highest-frequency bloodwork situations in veterinary oncology.

A lymphoma diagnosis is frightening, but dogs tolerate chemotherapy far better than humans. Most maintain a good quality of life throughout treatment. This guide covers what to expect — from first symptoms through the full treatment course.

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Types of Lymphoma in Dogs

Lymphoma is not one disease — the type determines prognosis and treatment response:

Multicentric (80% of cases)

Most common

Affects multiple lymph nodes throughout the body simultaneously. The classic presentation: firm, painless lymph node enlargement under the jaw, shoulders, and behind the knees. Dogs often feel well initially despite significant internal disease.

Alimentary (GI)

More aggressive

Affects the stomach and intestines. Symptoms: vomiting, diarrhea, weight loss, protein-losing enteropathy (low albumin). Harder to treat than multicentric. Often T-cell type with a worse prognosis.

Mediastinal

Urgent

Affects lymph nodes in the chest. Causes difficulty breathing, exercise intolerance, and swelling of the face and front legs. Often associated with hypercalcemia and T-cell type. Can cause pleural effusion requiring drainage.

Cutaneous

Rare

Affects the skin — raised plaques, ulcers, or nodules. Can be itchy. Typically T-cell type. Slower-growing but difficult to treat long-term.

B-Cell vs T-Cell: Why It Matters

Immunophenotyping — determining whether the cancer is B-cell or T-cell origin — is now considered standard of care before starting treatment. It directly affects prognosis and protocol choice:

	B-Cell	T-Cell
Frequency	~80% of cases	~20% of cases
Remission rate (CHOP)	70–90%	50–70%
Median survival (CHOP)	12–14 months	6–9 months
Hypercalcemia risk	Less common	Common (10–40%)

B-Cell (80%)

Remission: 70–90% with CHOP

Median survival: 12–14 months

Hypercalcemia: less common

T-Cell (20%)

Remission: 50–70% with CHOP

Median survival: 6–9 months

Hypercalcemia: common (10–40%)

Symptoms of Lymphoma in Dogs

Common Early Signs

• Painless swollen lymph nodes (jaw, shoulders, knees)
• Lethargy or reduced exercise tolerance
• Decreased appetite
• Weight loss
• Many dogs feel completely normal

Signs of Advanced Disease

• Increased thirst and urination (hypercalcemia)
• Vomiting or diarrhea (GI involvement)
• Difficulty breathing (chest involvement)
• Facial or limb swelling
• Pale gums (anemia)

Staging: How Far Has It Spread?

The WHO staging system for canine lymphoma (Stages I–V) guides treatment intensity and helps predict outcomes:

Stage	Extent
Stage I	Single lymph node or lymphoid tissue in a single organ
Stage II	Multiple lymph nodes in one region
Stage III	Generalized lymph node involvement
Stage IV	Liver and/or spleen involvement
Stage V	Bone marrow, blood, or other organ involvement (leukemic phase)

Each stage is further classified as a (no systemic signs) or b (systemic signs present). Stage Vb has the worst prognosis.

Track your dog's CBC across every chemo appointment

CHOP protocol involves 6+ months of regular bloodwork. Upload each panel to VetLens to see neutrophil and platelet trends — and understand which numbers are delaying or clearing treatment.

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What Bloodwork Shows

Bloodwork alone cannot diagnose lymphoma, but it reveals the disease's impact and guides treatment decisions:

CBC — Anemia

Normocytic, normochromic anemia from bone marrow involvement or chronic disease. Mild in early stages, more pronounced as disease progresses.

CBC — Neutropenia

Low neutrophils during chemotherapy. CBC is checked before every treatment — if neutrophils are below threshold, treatment is delayed by one week.

CBC — Thrombocytopenia

Low platelets from bone marrow involvement or immune-mediated destruction. Bruising or bleeding may occur.

Calcium (Ca)

Elevated in 10–40% of T-cell lymphoma cases (hypercalcemia of malignancy). Causes increased thirst, urination, weakness, and kidney damage if untreated. See our article on high calcium in dogs.

Albumin

Low albumin with GI lymphoma (protein-losing enteropathy) or advanced liver involvement.

ALP + ALT

Elevated if lymphoma has infiltrated the liver. Significant elevation suggests hepatic involvement.

LDH

Lactate dehydrogenase is elevated in active lymphoma and may track treatment response, though it's not universally checked.

Note

Normal Bloodwork Does Not Rule Out Lymphoma

Many dogs with early multicentric lymphoma have completely normal CBC and chemistry values. Enlarged lymph nodes are the diagnostic clue — not blood values. Fine needle aspirate of a lymph node confirms the diagnosis.

Diagnosis: How Lymphoma Is Confirmed

1. Fine Needle Aspirate (FNA)
A needle is inserted into an enlarged lymph node to collect cells for cytology. Quick, minimally invasive, done in-office. Confirms lymphoma in most cases but can't reliably determine cell type.
2. Lymph Node Biopsy
Full lymph node removal for histopathology. More definitive than FNA. Required for some subtypes and for grading (low-grade vs high-grade).
3. Immunophenotyping
Flow cytometry or immunohistochemistry determines B-cell vs T-cell origin. PARR (PCR for antigen receptor rearrangement) is used when cytology is inconclusive. This step is now standard of care — it changes the prognosis and sometimes the protocol.
4. Staging Workup
Once lymphoma is confirmed: full bloodwork, urinalysis, chest X-rays, abdominal ultrasound, and possibly bone marrow aspirate to determine extent of disease.

Treatment Options

CHOP Protocol

Gold standard

Multi-drug chemotherapy over 19–25 weeks: Cyclophosphamide, Hydroxydaunorubicin (doxorubicin), Oncovin (vincristine), Prednisone. Best remission rates and longest survival. Requires weekly clinic visits initially. CBC checked before each treatment.

Prednisone Alone

Palliative

When full chemotherapy is not possible due to cost or owner preference. Causes temporary remission in some dogs (weeks to months) but shortens the window for CHOP to work if pursued later. Median survival: 1–2 months.

Single-Agent Doxorubicin

Compromise option

Less intensive than CHOP, fewer clinic visits. Remission rate ~50–75% for B-cell. Median survival 6–9 months. A reasonable middle ground for some families.

Rescue Protocols

After relapse

When lymphoma relapses after CHOP, rescue protocols (MOPP, LOPP, rabacfosadine/Tanovea) can achieve a second remission. Response rates and duration are generally lower than first-line treatment.

Good News

Dogs Tolerate Chemo Better Than You Think

Unlike human chemotherapy, the goal in veterinary oncology is quality of life, not cure. Doses are calculated to minimize side effects. About 75–80% of dogs experience mild or no side effects. Serious complications (hospitalization-requiring neutropenic fever) occur in roughly 5% of treatments. Most dogs eat normally, play, and feel well throughout the protocol.

Monitoring During CHOP Chemotherapy

Dogs on CHOP require frequent bloodwork — this is unavoidable. Here's what owners should expect:

• CBC before every treatment: Neutrophils must be above threshold (typically >2,000–3,000/μL) to proceed. Platelets are also checked. If counts are too low, treatment is delayed one week.
• Chemistry panel periodically: Liver and kidney function checks, especially before doxorubicin (cardiotoxic at high cumulative doses) and cyclophosphamide.
• Nadir monitoring: The lowest blood counts typically occur 7–10 days post-treatment. Some protocols include a mid-cycle CBC check.
• Remission assessment: Physical exam and lymph node measurement at each visit. Ultrasound or advanced imaging at protocol milestones.

Warning

Neutropenic Fever: Watch for This at Home

If your dog has a fever (rectal temperature >103°F / 39.4°C) within 7–10 days of chemotherapy, call your oncologist immediately — this is a medical emergency. Neutropenic fever requires IV antibiotics. Keep a thermometer at home during treatment.

Questions About Your Dog's Lymphoma Bloodwork?

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Good News

Key Takeaway

Lymphoma is serious, but it's also the most treatable cancer in dogs. B-cell lymphoma has a 70–90% remission rate with CHOP, and most dogs maintain quality of life throughout treatment. Knowing the cell type before starting is critical — ask your oncologist about immunophenotyping if it hasn't been done.

The bloodwork during treatment is not incidental — it's how your oncologist keeps your dog safe. Upload each panel so you can see the full picture across the protocol, not just the result from today's visit.

Track Your Dog's Lymphoma Treatment

Upload each pre-treatment CBC to VetLens and see:

✓ Neutrophil and platelet trends across the full CHOP protocol
✓ Liver and kidney values at each chemistry check
✓ Side-by-side comparison to see how counts recover between treatments
✓ Plain-language explanation of what each result means

Analyze My Dog's Bloodwork

Frequently Asked Questions

What is lymphoma in dogs?

Lymphoma is cancer of the lymphocytes, a type of white blood cell. It's one of the most common cancers in dogs and can affect lymph nodes, spleen, liver, GI tract, bone marrow, or skin. The most common form causes painless swollen lymph nodes throughout the body.

What are the first signs of lymphoma in dogs?

The most common early sign is firm, painless swollen lymph nodes — especially under the jaw, in front of the shoulders, or behind the knees. Many dogs feel completely normal at this stage. Lethargy, weight loss, and decreased appetite develop as disease progresses.

How long can a dog live with lymphoma?

Without treatment: 4–6 weeks. With prednisone alone: 1–2 months. With single-agent doxorubicin: 6–9 months. With full CHOP chemotherapy for B-cell lymphoma: median 12–14 months, with about 25% surviving 2+ years. T-cell lymphoma has a worse outlook: median 6–9 months with CHOP.

What is CHOP chemotherapy for dogs?

CHOP is the standard multi-drug protocol: Cyclophosphamide, Hydroxydaunorubicin (doxorubicin), Oncovin (vincristine), and Prednisone, given over 19–25 weeks. It achieves remission in 70–90% of B-cell cases. CBC is checked before every treatment to ensure safe white blood cell and platelet counts.

Do dogs suffer during chemotherapy?

Most dogs tolerate veterinary chemotherapy well. Doses are calculated for quality of life, not cure. About 75–80% of dogs experience mild or no side effects. Serious complications requiring hospitalization occur in roughly 5% of treatments. Most dogs eat and play normally throughout the protocol.

What does high calcium mean with dog lymphoma?

Hypercalcemia occurs in 10–40% of dogs with T-cell lymphoma. It's caused by the tumor releasing a hormone-like substance (PTHrP) that raises blood calcium. Signs include increased thirst, urination, weakness, and vomiting. Untreated hypercalcemia causes kidney damage — it requires prompt treatment alongside lymphoma therapy.