What are the common symptoms of canine lymphoma?

Common symptoms of canine lymphoma include lethargy, loss of appetite, weight loss, and repeated vomiting or diarrhea. Some dogs will have visibly swollen lymph nodes. If you are concerned, consult your vet.

What tests does the vet use to help diagnose this condition?

Common tests include a complete blood count and biochemistry panel, urinalysis, chest and abdominal X-rays, and abdominal ultrasound. If needed, fine-needle aspiration or tissue biopsy may be performed for a pathological diagnosis, along with immunohistochemistry or PCR to classify the type.

What treatment options are available for canine lymphoma?

Treatment may include supportive care, corticosteroids, chemotherapy, or localized surgery. An experienced veterinary team will assess each patient individually and arrange follow-up monitoring. Discuss the most suitable plan with your vet.

What information should I bring to the appointment?

Record the onset and progression of symptoms, bring a daily log of food intake and bowel movements, short video clips, a recent weight history, and any prior test results or imaging. A list of all current medications and supplements is also helpful.

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

Canine Lymphoma in Dogs: Symptoms, Diagnosis & Treatment [2025]

Canine lymphoma is one of the most common cancers in dogs, often first presenting as swollen lymph nodes. The CHOP chemotherapy protocol achieves remission rates of 80–90%.

Take 1 minute to check the symptoms first

Last updated: 2026/01/05

Pethealthmap Editorial Team

Sources: ACVIM, WSAVA, National Taiwan University Veterinary Hospital

When to See a Vet

Seek Emergency Care Immediately

•Unable to stand or loss of consciousness
•Rapid breathing, labored breathing, or open-mouth breathing
•Persistent heavy vomiting or inability to drink water for more than one day

Schedule a Clinic Visit Soon (within 24–72 hours)

•Noticeably decreased appetite lasting more than two days
•Repeated vomiting or increasing frequency of diarrhea
•Visible lump or enlargement appearing on the neck or body

01What symptoms indicate something is wrong?

Canine lymphoma often causes systemic changes including shifts in energy and appetite, gastrointestinal signs, and weight loss. Some dogs will have visibly or palpably enlarged lymph nodes.

Lethargy and noticeably reduced activity
Persistent loss of appetite or significant decrease in food intake
Repeated vomiting or increased frequency of diarrhea
Unintentional and ongoing weight loss
Palpable swollen lymph nodes in the neck or abdomen

Seek emergency care immediately if you notice the following symptoms:

⚠️ Unable to stand on their own or unresponsive
⚠️ Rapid breathing, labored breathing, or open-mouth breathing
⚠️ Persistent vomiting or inability to drink water for more than a day

02How can I tell at home if something is wrong? What to watch for and when to seek emergency care

Keeping detailed records of what you observe at home helps your vet assess the progression of illness and prioritize what needs attention first.

Record changes in energy, activity level, and any unusual behavior daily
Note daily food intake, any picky eating, or refusal to eat
Use your phone to log the frequency, timing, and appearance of vomit
Monitor stool frequency, consistency, and presence of blood
Weigh your dog weekly at a set time and track the trend
Seek veterinary care promptly if symptoms worsen or breathing difficulties develop

03How does the vet diagnose this? Common diagnostic tests

Your vet will begin with a physical examination and baseline tests, then arrange further imaging or pathological workup as needed to confirm the diagnosis and determine the stage.

Complete blood count and biochemistry panel to assess overall organ function

Urinalysis to evaluate urinary tract and metabolic health

Chest and abdominal X-rays to check organ size and detect any spread

Abdominal ultrasound to assess internal organs and lymph node size

Cytology (fine-needle aspiration) or tissue biopsy to obtain pathological samples

Immunohistochemistry or gene testing (PCR) to assist with pathological classification

Electrocardiogram (ECG) if indicated, to assess cardiac function and anesthetic risk

04What treatments and follow-up care are available?

Treatment and follow-up are tailored to the individual patient and may include supportive care, medications, and regular monitoring to assess response to therapy and maintain quality of life.

IV fluid support to correct dehydration and electrolyte imbalances
Corticosteroids may improve appetite and energy levels in the short term
Chemotherapy should be planned and monitored by an experienced oncology team
Localized masses can be evaluated by a specialist for potential surgical removal
Regular rechecks and blood tests are required during treatment to monitor for side effects
Pain or discomfort should be managed with medications adjusted by your vet

05What should I prepare before the appointment? Key information to help your vet diagnose quickly

Record when symptoms started, how they have changed, and how severe they are

Bring a daily log of diet, vomiting, and bowel movements, plus short video clips

Prepare a recent weight history and description of body condition

Bring a list of all current medications and supplements

If you have prior test results or imaging (X-rays, ultrasound), bring those along

Consider booking a vet with oncology or internal medicine experience

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.

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