Although no one likes to think of the worst with our furry companions, cancer in dogs is more common than we realize.

Leukemia in dogs is a type of cancer that results in an increased white blood cell count in the bone marrow and bloodstream.

These conditions can be chronic or acute, with acute being more malignant. There are two main types of canine leukemia.

The first type is lymphocytic leukemia. This type of cancer occurs when cancerous cells reside in the lymph nodes.

The second type is myelogenous leukemia. This happens when the cancerous cells are in the bone marrow.

Leukemia in Dogs: Acute Lymphocytic Leukemia (ALL)

Acute lymphocytic leukemia is characterized by high populations of lymphoblasts, also known as immature lymphocytes.

This condition will typically occur in younger dogs, with the average age of diagnosis being 6.2 years old.

Slightly more than one-quarter of all affected dogs under the age of four will develop this condition.

During the examination, the dogs will typically have a deficiency of a variety of blood cells, primarily due to the dominance of the cancerous white blood cell production rates.

A dog presenting with canine leukemia will periodically have enlarged livers and spleens. Frequently, they could also have enlarged lymph nodes.

Often, canines will be deficient in platelets, red blood cells, and some types of white blood cells called neutrophils.

Unfortunately, the aggressive nature of ALL makes a full recovery almost impossible.

Even with treatment, many dogs succumb to the disease. Without treatment, dogs could die within weeks.

dog leukemia

Chronic Lymphocytic Leukemia in Dogs (CLL)

Chronic Lymphocytic Leukemia (CLL) is much less severe than ALL. It primarily occurs in older dogs, typically between 10 and 12.

There are three known types of CLL, all impacting the dog differently. It is essential to perform a blood test to reveal which kind of CLL a dog has.

For example, dogs with the T-cell version of CLL holds the best projection survival rates and time. CLL is generally less malignant than ALL.

Frequently, many dogs fail to show symptoms of CLL. In these situations, diagnosis often occurs during routine bloodwork.

The vet may not require treatment if the pet does not have signs and holds a lymphocyte count below a certain level.

Many dogs diagnosed with CLL can still live several years after the initial diagnosis, commonly keeping a good quality of life.

How Do Veterinarians Distinguish Between Acute and Chronic Conditions?

A veterinarian will always look for a few key markers when trying to determine whether your dog has ALL or CLL.

The age of your dog will be the first deciding factor, along with any symptoms your dog is experiencing.

ALL often takes a more significant and visible toll on the dog, frequently appearing in younger canines.

The maturity of lymphocytes is also a tool veterinarians will use to determine whether it's ALL or CLL.

Cancerous cells in dogs with chronic conditions will frequently have had time to develop and mature than dogs with acute leukemia.

RELATED: Everything You Need to Know About Canine Cancer

leukemia in dogs symptoms

Staging of Leukemia in Dogs

Most cancers offer specific staging as part of the diagnosis. This staging will include the size of the tumor and whether cancer has spread throughout the body.

This becomes difficult with ALL and CLL, as there is no mass to analyze. Leukemia is a blood cancer that can spread quickly, often before diagnosis.

Instead, the World Health Organization classifies ALL through the type of lymphocytes involved. CLL uses the Rai system in stages.

Treating Canine Leukemia

Many cases of leukemia in dogs can be managed or treated, but unfortunately, the condition is rarely cured.

Often the goal of treatment is to try and restore the proper white blood cell production while reducing symptoms and relieving discomfort for the dog.

Chemotherapy is the typical treatment for canine leukemia. Although this method doesn't cure the condition, it can put cancer into remission or slow growth overall.

Acute leukemia is more likely to be fatal compared to chronic leukemia, frequently requiring immediate and aggressive care.

Most often, treatment includes antibiotics, intravenous fluids, and blood transfusions should the dog have anemia.

Occasionally, the dog may require a feeding tube if it can't successfully eat on its own.

Veterinarians can use a few chemotherapy drugs to treat acute leukemia. These drugs include vincristine, prednisone, cyclophosphamide, doxorubicin, and L-asparaginase.

Chronic leukemia may not initially require treatment at first. The diagnosis will require strict monitoring over time.

As the condition begins to worsen, the veterinarian may administer oral chemotherapy drugs, including cyclophosphamide, chlorambucil, and prednisone.

The veterinarian may prescribe more aggressive treatment if cancer spreads to other areas within the body.

While dietary changes, supplements, and alternative medicine won't cure leukemia, they can help strengthen the dog's immune system.

This strengthening can prevent secondary infections that your dog may experience, especially if they require chemotherapy.

leukemia in dogs chemotherapy

Understanding a Leukemia Diagnosis

The most apparent sign of leukemia in dogs is lymphocytosis, where the animal produces more lymphocytes than average.

In healthy dogs, approximately 3,500 lymphocytes exist in a microliter of blood.

In leukemic dogs, the lymphocytes can become as high as 100,000 per microliter of blood.

Situations that hold lymphocytes higher than 20,000 or more allow a simplified diagnosis. When there are less extreme increases in lymphocytes, it's often harder to pinpoint the reasoning.

Less obvious reasons could be a sign of many different health problems within the dog. Leukemia may be in the early stages when production hasn't hit the highest levels.

Alternatively, it could be that the leukemia is in the latent stages, with bone marrow becoming so damaged it can no longer produce many cells.

Leukemia in Dogs: Alternative Diagnosis

Although the probability is minimal, an early diagnosis of leukemia may mimic many other conditions. These conditions include the following possibilities:


Leukemia will impact the bone marrow and blood directly. This blood cancer can periodically affect lymphocyte cells.

Lymphoma is when you seldom see lymphocyte counts above 20,000 per microliter. The lymphoma will often impact the lymph nodes and other tissues.


Occasionally, blood parasites will increase lymphocyte levels above 6,000 per microliter.

The vet may perform special tests to determine whether your dog has CLL or a parasite.


Acute stress can tax the body, increasing the number of lymphocytes in your dog's blood work.

Increases can be considerable, occasionally hitting 15,000 lymphocytes per microliter.

Fungal Infections

Like the blood parasite, severe fungal infections will increase lymphocyte counts. A few infections could bring your dog's lymphocyte count above 6,000 per microliter.

leukemia dog cancer

Natural Choices for Leukemia in Dogs

The main focus of any cancer is to strengthen your dog's overall health and immune system.

Natural approaches may help improve the quality of your dog's life, although they won't cure leukemia. Here are a few natural options that can support your dog's health:

Stop Vaccinating Your Dog

Vaccines can potentially cause many long-term health problems in dogs, which may encourage the growth and development of cancer in several ways.

Veterinarians should never administer vaccinations to unhealthy dogs.

Switch to Fresh Food

Cancer cells thrive on sugars, including starchy carbohydrates found within kibble.

The sugar will fuel cancer by increasing insulin (helping the cells grow and reproduce) and adding to inflammation. Additionally, kibble can contain carcinogenic substances.

Feed your dog fresh, whole foods, including grass-fed meats and organs. Organs are often nature's multivitamins full of essential nutrients for your dog.

Symptoms of leukemia may ultimately worsen over time, resulting in death if left untreated.

If you see the signs of cancer in your dog, always consult a veterinarian immediately.

Add Supplements

There are many different supplements available to help your dog manage his cancer.

Great options include antioxidants to protect your dog's cells from damage done by free radicals.

The damage can lead to cancer and other chronic conditions. Probiotics and antioxidants are wonderful ways to boost your dog's immune system.

leukemia in dogs fatigue

Symptoms of Leukemia in Dogs

The symptoms of leukemia will vastly vary depending on their type and whether the condition is chronic or acute.

Most often, acute canine leukemia will affect middle-aged to senior dogs, commonly after the age of six.

Acute canine leukemia symptoms will worsen rapidly. The veterinarian and owner must treat these symptoms immediately for optimal success.

Here are a few symptoms of acute leukemia that every pet owner should look for:

  • Pale or white color in the tongue or gums
  • Lack of appetite or weight loss
  • Weakness
  • Vomiting
  • Fever
  • Increased thirst or general dehydration
  • Irregular heart rate or breathing
  • Bruising or bleeding easily
  • Lethargy
  • Chronic diarrhea
  • Recurring infections or delayed healing
  • Aggression or sudden behavioral changes

The symptoms of chronic leukemia may not be as easy to identify. The condition may take months or years to develop fully.

Occasionally, some dogs won't show signs of leukemia when they receive the diagnosis.

Usually, chronic leukemia impacts senior dogs ten years or older. Many times, this condition is uncovered during routine blood work.

A few symptoms appear with chronic leukemia, which all tend to worsen over time.

  • Loss of appetite
  • Lethargy
  • Anemia
  • Enlargement of the spleen
  • Swelling in the lymph nodes
  • Bleeding or bruising easily

These symptoms are often like other forms of cancer, autoimmune diseases, and other conditions.

It's essential to visit your vet quickly for a proper diagnosis. Early treatment will often lead to a better outcome.

dog leukemia treatment

Leukemia in Dogs Causes

Unfortunately, the causes of leukemia in dogs aren't well understood. Most of the time, veterinarians believe the development will start spontaneously from a mutation within the bone marrow.

Certain factors can create an increased risk of developing the condition. These risk factors include exposure to radiation or toxic chemicals or facing certain viral infections.

How to Diagnose Leukemia

The veterinarian will want to perform different blood tests to rule out other causes to receive a leukemia diagnosis.

These blood tests will provide critical information about what's happening within your dog's body.

These blood tests include the following details:

Complete Blood Count (CBC): This test looks at the different types of cells within the dog's blood.

White Cell Differential: This test will look at the blood's number and types of WBCs. Abnormalities can often help determine a diagnosis.

Cytology: These tests are handy when diagnosing leukemia. They will tell the vet the shape and quantity of the cells.

Cytology will look at different abnormalities within the blood. Abnormalities in lymphocytes can confirm leukemia.

Flow Cytometry: This test will look at different cell markers and try to figure out what type of cells they are.

The test can also confirm cells are leukemic and will aid in determining the stage of cancer.

Immunophenotyping: The test will help identify cancerous cells in the blood. It can also help determine which cells are affected so a vet knows which type of leukemia the dog has.

Polymerase Chain Reaction (PCR) Test: If all cells look alike (commonly called cell clonality), it confirms your dog has leukemia.

With leukemia, abnormal cells will derive from a single cell. PCR tests let labs rapidly multiply samples to determine cell clonality.

Vets can make a CLL diagnosis using a blood test for diagnosis. Most of these techniques can also test bone marrow through aspiration or biopsy.

The tests are frequently invasive and can cause long-lasting discomfort or infection. If possible, avoid these tests.

A bone marrow biopsy is necessary to confirm any ALL diagnosis. Bone marrow must contain 20-25% blasts to be a positive result.

Leukemia in Dogs: Conclusion

Although no one wants to receive a leukemia diagnosis for their furry companion, having a better understanding of what the condition entails and the treatment available can help you make an informed decision.

Most importantly, always speak with your vet about the best approach for your dog overall.

Just as the signs, symptoms, and prognosis will vary, so will the approach your vet recommends taking.

Ultimately, considering the dog's physical health and quality of life should always take top priority when making these treatment decisions.

READ NEXT: What To Do If You Can’t Afford Your Dog’s Cancer Treatment