Understanding Canine Lymphoma

Few words are more frightening to hear than “Your dog has cancer.” If your veterinarian has diagnosed your dog with lymphoma, it’s completely normal to feel overwhelmed.

At Cascade Heights Veterinary Center, we believe that understanding the disease and your treatment options can help you make informed decisions for your pet and your family. While lymphoma is a serious diagnosis, there are several treatment options available, and our team is here to guide you through every step of the process.

What Is Lymphoma?

Lymphoma is a cancer of the lymphocytes, a type of white blood cell that plays an important role in the immune system. Because lymphocytes travel throughout the body, lymphoma is considered a systemic disease, meaning it affects the body as a whole rather than a single organ.

Lymphoma most commonly develops in the lymph nodes, but it can also affect the:

  • Spleen
  • Liver
  • Bone marrow
  • Gastrointestinal tract
  • Chest
  • Skin
  • Other organs

Because lymphoma can involve many different tissues, every dog’s disease may look a little different.

What Are the Signs of Lymphoma?

The most common sign is enlarged lymph nodes. Owners often notice firm, painless swellings beneath the jaw, in front of the shoulders, or behind the knees.

Other signs may include:

  • Decreased appetite
  • Weight loss
  • Lethargy
  • Increased thirst or urination
  • Vomiting or diarrhea
  • Difficulty breathing (if the chest is involved)
  • Skin lesions (in certain forms of lymphoma)

Some dogs feel completely normal despite having significantly enlarged lymph nodes.

How Is Lymphoma Diagnosed?

In many cases, lymphoma can be diagnosed with a fine needle aspirate (cytology).

Using a small needle, your veterinarian collects cells from an enlarged lymph node or affected tissue and examines them under the microscope. This simple, minimally invasive procedure is often enough to diagnose lymphoma.

In some cases, additional testing may be recommended to better classify the cancer.

Why Are Additional Tests Sometimes Needed?

Although cytology tells us that lymphoma is present, it doesn’t always tell us what type of lymphoma your dog has.

Additional tests such as flow cytometry, PARR (PCR for Antigen Receptor Rearrangements), or occasionally a biopsy can help determine:

  • The specific subtype of lymphoma
  • Whether the lymphoma involves B-cells or T-cells
  • Expected response to treatment
  • Overall prognosis

These advanced tests allow veterinarians and oncologists to recommend the most appropriate treatment plan.

Why Isn’t Surgery an Option?

Unlike many cancers that begin as a single lump or mass, lymphoma affects cells that circulate throughout the body.

Because of this, surgery is not considered an effective treatment. Even if one enlarged lymph node is removed, cancer cells remain elsewhere in the body.

Instead, treatment focuses on medications that target cancer cells throughout the entire body.

What Are My Dog’s Treatment Options?

Every family has different goals, finances, and circumstances. Fortunately, lymphoma offers several treatment options.

Injectable Chemotherapy

Referral to a veterinary oncologist for injectable chemotherapy offers the greatest opportunity for remission.

Modern veterinary chemotherapy is very different from what many people imagine. The goal is to maintain an excellent quality of life while controlling the cancer. Most dogs tolerate treatment surprisingly well and continue to enjoy their normal daily activities.

Although this option involves the most frequent veterinary visits and is the most expensive, it also provides the greatest potential for disease control.

Oral Chemotherapy

Some dogs are good candidates for oral chemotherapy medications that can be administered at home.

These treatments require periodic blood work to monitor for side effects but allow much of your dog’s care to remain with your primary veterinarian. While oral chemotherapy may not achieve the same results as full injectable protocols, it can still provide meaningful disease control for many patients.

Palliative Steroid Therapy

For families who choose comfort-focused care, prednisone (or another corticosteroid) can temporarily shrink lymphoma and improve quality of life.

Steroid therapy is inexpensive and requires relatively little monitoring, but it is considered palliative rather than curative. Most dogs eventually become resistant to steroids over time, and the average response lasts approximately three months.

Your veterinarian can help you determine whether this option best aligns with your goals for your pet.

Should My Dog Have Cancer Staging?

If chemotherapy is being considered, your veterinarian may recommend cancer staging.

Staging helps determine how extensively the lymphoma has affected the body and provides valuable information when developing a treatment plan.

Common staging tests include:

  • Complete blood work
  • Chest radiographs (X-rays)
  • Abdominal ultrasound
  • Additional sampling of affected tissues when appropriate

While staging is highly recommended before chemotherapy, it may be less essential if your family has elected comfort-focused care.

What Is the Prognosis?

The prognosis for lymphoma varies significantly depending on several factors, including:

  • The specific subtype of lymphoma
  • Whether it is B-cell or T-cell lymphoma
  • The stage of disease
  • Your dog’s overall health
  • Response to treatment

Advanced testing, such as flow cytometry or PARR, can provide more individualized prognostic information and help guide treatment recommendations.

What Happens Next?

A lymphoma diagnosis can feel overwhelming, but you don’t have to make every decision today.

Take time to discuss your goals, ask questions, and consider which treatment option best fits your family. Whether you pursue referral to a veterinary oncologist, oral chemotherapy with your primary veterinarian, or comfort-focused care, our goal is always the same—to help your dog maintain the best possible quality of life.

We’re Here to Help

At Cascade Heights Veterinary Center, we understand that a cancer diagnosis affects the entire family. We’re here to answer your questions, explain your options, coordinate care with veterinary oncologists when needed, and support you every step of the way.

If your dog has recently been diagnosed with lymphoma, please don’t hesitate to reach out. Together, we’ll develop a treatment plan that is tailored to your pet and your family’s goals.