Understanding Canine Lymphoma: What Pet Owners Need to Know 🐾

Hearing that your dog may have cancer is one of the most worrying moments for any pet owner. At our practice, we believe knowledge is power — and the more you understand about conditions like canine lymphoma, the better equipped you’ll be to make decisions that help your pet live a happy and comfortable life.

What is Canine Lymphoma?

Canine lymphoma is a type of cancer of the lymphatic system, which is an important part of the immune system. It develops when lymphocytes (a type of white blood cell that normally helps fight infection) grow uncontrollably.

Lymphoma is one of the most common cancers in dogs, accounting for about 10–20% of all canine cancers.

Common Signs to Look Out For

Canine Lymphoma can show itself in different ways, but some of the most common symptoms include:

Enlarged, firm lymph nodes (often felt under the jaw, behind the knees, or in the armpits)
Tiredness or reduced energy
Loss of appetite or weight loss
Increased thirst and urination
Vomiting, diarrhoea, or digestive upset (if the stomach or intestines are affected)
Breathing difficulties (if the chest is involved)

If you notice any unusual lumps or changes in your dog’s behaviour, it’s always best to get them checked.

How is Canine Lymphoma Diagnosed?

Your vet may suggest:

Physical examination to check lymph nodes
Fine needle aspirate or biopsy to examine cells under a microscope
Blood tests or imaging (such as X-rays or ultrasound) to see if other organs are involved

These tests help us understand the type of lymphoma and the best treatment approach.

Because lymphoma can mimic other conditions, proper diagnosis is essential. Vets use a combination of physical exams, laboratory tests, and imaging to confirm the disease and guide treatment.

1. Physical Examination

The first step is often noticing enlarged lymph nodes (under the jaw, behind the knees, or in the armpits).
Your vet may also check for organ enlargement (liver, spleen) or signs such as weight loss or lethargy.

2. Fine Needle Aspirate (FNA)

A quick, minimally invasive test where a thin needle collects cells from an enlarged lymph node or organ.
These cells are examined under a microscope by a veterinary pathologist.
In most cases, FNA can confirm lymphoma.

3. Biopsy

Sometimes a tissue biopsy is recommended if FNA results are unclear.
This involves removing a small piece of tissue from the lymph node (often under sedation or anaesthetic).
Biopsy provides more detail about the cancer type.

4. Blood & Urine Tests

These help assess your dog’s overall health and organ function.
Some dogs with lymphoma may show changes such as high calcium levels (common in T-cell lymphoma).

5. Imaging (X-rays or Ultrasound)

Used to see if internal organs (like the chest, abdomen, liver, or spleen) are affected.
Helps with staging the disease and planning treatment.

6. Advanced Tests (for Treatment Planning)

Flow cytometry or immunohistochemistry: used to identify whether the lymphoma is B-cell or T-cell.
Bone marrow aspirate: sometimes performed to check if the cancer has spread into the bone marrow.

✅ Together, these tests don’t just confirm the diagnosis — they also tell your vet how advanced the disease is and which treatment plan will likely work best.

Treatment Options

While lymphoma is usually not curable, it can often be managed very successfully, allowing many dogs to enjoy a good quality of life. Treatment options include:

Chemotherapy – the most effective option. Dogs generally tolerate chemotherapy much better than people, with fewer side effects.
Steroids – can temporarily shrink swollen lymph nodes and improve comfort, though usually for a shorter time.
Other therapies – like surgery or radiation, used in specific cases.

What’s the Outlook?

With chemotherapy, many dogs can go into remission, living 6–12 months or longer with good quality of life.
With steroids alone, survival is usually 1–3 months.
Without treatment, lymphoma tends to progress quickly, often within weeks.

Quality of Life in Treated Dogs

A key point many owners worry about is whether chemotherapy will make their pet feel sick, as it often does in humans. In dogs, chemotherapy protocols are designed to prioritise quality of life over maximum drug dose.

Most dogs tolerate it well, with only mild side effects like temporary tummy upset or reduced appetite.
Less than 25% of patients experience noticeable side effects, and fewer than 5% need hospitalisation for them.

Emerging Therapies

Research is ongoing into new ways of managing canine lymphoma, including:

Targeted therapies (such as monoclonal antibodies that specifically attack cancer cells)
Bone marrow transplantation in specialised centres
Immunotherapy approaches similar to those being developed in human medicine

These are not yet widely available but represent hopeful areas of progress.

Final Thoughts

A diagnosis of canine lymphoma can feel overwhelming, but remember — you are not alone. Many dogs respond very well to treatment and enjoy many more months of comfort, play, and companionship.

If you’ve spotted unusual lumps or have concerns about your pet’s health, please don’t hesitate to contact us. Early action can make a huge difference. ❤️🐶