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My Dog Has Cancer, Now What?


If you’ve found yourself here because you recently had a pet diagnosed with cancer – we are so sorry. We hope you can find some valuable information and arm yourself with more knowledge to get through this difficult season.

Cancer is one of the most feared diagnoses both in human and veterinary medicine. The word alone spells defeat in the minds of those who are diagnosed and marks the beginning of a new battle.

Due to advancements in medicine, companion animals are living longer, making cancer diagnoses more common in senior pets. According to the American Animal Hospital Association (AAHA), there are 6 million new cancer diagnoses in dogs every year.

This number would likely rise significantly if every pet saw a veterinarian on a regular basis. AAHA also estimates that 1 in 4 dogs will develop cancer at some point in their lifetime.

Cancer can affect any part of the body in animals, and it's important for pet owners and veterinary healthcare providers to understand how to manage cancer and provide optimal patient care. Let’s get into the most common varieties of cancer we see in dogs, some of the signs and symptoms, care options for your pet, as well as end-of-life care plans.

Let’s get started.

Veterinarian and Vet Tech examine orange Pomeranian on exam table

Common Forms of Cancer in Dogs

As mentioned, cancer can take many forms in the body and affect many different types of tissues. Common cancers include:


Breeds commonly affected: Golden Retrievers

The term “lymphoma” describes several types of cancers that originate from white blood cells called lymphocytes. These cells are a normal worker in the immune system that responds to foreign cells within the body to prevent and clear infection.

Lymphoma attacks the lymph nodes which are located across multiple areas of the body. It is one of the most commons cancer types seen in dogs, and they are 2 to 5 times more likely than humans to develop lymphoma. Common symptoms include swelling of the face, neck, and legs, as well as inappetence, lethargy, and weight loss.

Lymphoma is frequently diagnosed through physical examination and pathology of the lymph nodes. Upon diagnosis, your veterinarian can discuss treatment options. The life expectancy with most types of lymphoma is limited to 2-3 months without chemotherapy treatment. Some treatment protocols used have achieved longer lifespans, with a median length of survival between 9-13 months.


Commonly affects: Large breeds, such as Great Danes and Mastiffs

Osteosarcoma is the most common type of bone cancer seen in dogs. This type of cancer can attack any bone, but it typically affects the long bones (like the femur) of large breed dogs. Symptoms include lameness, pain in the limb, and swelling.

This cancer progresses quickly and can spread to other bones or organs. Due to the aggressive nature of this cancer, many clinicians will advocate for amputation of the affected limb.

Dogs do well with three limbs, and surgery can lengthen their life expectancy. Chemotherapy may also be advised to attack any cancer cells that have metastasized to other regions of the body.

Senior Golden Retriever lies on stone floor


Breeds commonly affected: Golden Retrievers, German Shepherds, Skye Terriers

Hemangiosarcoma is a cancer that originates from cells that line blood vessels of the body. The most common organ to be impacted is the spleen. This is because the spleen's primary function is to filter and clean blood.

The spleen also contains many white blood cells and antibodies that help the body resist infection. Because the spleen is so vascular, the blood vessels there are susceptible to this type of cancer; however, it can also affect the heart, liver, and skin. This cancer is a silent killer because many times dogs do not show symptoms.

Tumors on the spleen grow over time until it reaches critical mass, and the tissue begins to rupture. Once this occurs, emergency surgery is required immediately to control blood loss and shock.

Because this happens quickly and without warning, many times treatment is too late. Symptoms to watch for are lethargy, stumbling, pale/white gums, or distended abdomen. Seek emergency veterinary care immediately.

Managing Canine Cancer

The management of cancer involves diagnosis, treatment, and long-term monitoring of the patient's condition. Diagnosis involves a thorough examination of the animal and various procedures such as blood tests, biopsies, and diagnostic imaging.

Following diagnosis your veterinarian can discuss available treatment options to you. Treatment options can include chemotherapy, surgery, radiation therapy, and immunotherapy.

The choice of treatment depends on various factors, including the type and grade of cancer, the animal's age and overall health status, and outcome expectations and financial constraints.

Closeup of tired, senior German Shepherd mix lying down on white blanket

Pain Management

Pain management is an essential aspect of patient care in veterinary medicine, especially for patients with cancer. Pain can affect the animal's appetite, sleep quality, and overall quality of life. There is absolutely no reason a patient should suffer from pain during treatment.

There are various pain management options available, including opioids, non-steroidal anti-inflammatory drugs (NSAIDs), and alternative therapies such as acupuncture and massage therapy. Providing effective pain management not only helps alleviate the animal's pain, but also promotes healing and improves their quality of life.


Nutrition is another critical aspect of patient care in veterinary medicine. In animals with cancer, maintaining proper nutrition is crucial for enhancing their immune system and promoting healing. However, many animals with cancer have reduced appetite or difficulty eating due to side effects of treatment, gastrointestinal issues, or discomfort.

There are medications that can help with these issues as well as appetite stimulants. Some owners may seek the advice of a veterinary nutritionist to ensure their pet is on the most effective food and supplement regime.

Mental and Emotional Support

Cancer not only affects the animal's physical wellbeing, but also their emotional and psychological wellbeing. Pets with cancer may experience anxiety, depression, and other behavioral changes that affect their quality of life.

Dogs experiencing anxiety and depression may have sleep disturbances, lose interest in common toys or activities, and “mope” around more often. No one wants to play when they don’t feel good. Increasing quality time with your pet can help them feel more comfortable as well as making sure their pain is managed correctly.

Senior white chihuahua lies on brown fleece blanket with head propped up looking at camera

Palliative and End-of-Life Care

In some cases, cancer may be incurable, or treatment may not be a viable option. In such cases, palliative care and end-of-life care play a crucial role in providing comfort and dignity to the animal.

Palliative care involves managing symptoms such as pain, anxiety, and nausea, and providing supportive care to improve the animal's quality of life. End-of-life care involves providing compassionate care during the animal's final days and ensuring a peaceful and dignified passing.

Humane Euthanasia is an option for terminal patients. Commonly referred to as “putting to sleep”, euthanasia is a painless, peaceful way to allow the passing of your pet, often sparing them from ongoing suffering from their illness.

Final Thoughts

Cancer is a leading cause of morbidity and mortality in pets, with up to 50% of all pets above 10 years of age being affected by the disease. Although veterinary oncology has advanced at a rapid rate and treatment options are growing, the cost of care is too high for many families. There are several payment options available including Care Credit. Also check to see if your veterinarian participates in Scratch Pay.

The care and quality of life of your pet is what matters most. They have served and loved you fully while being a part of your family. However you choose to treat your pet’s illness, do it with love, kindness, and compassion.

Stay well.

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About the Author

Tasha Nelson, M.S., Researcher and Veterinary Assistant

Tasha Nelson Phillips is a veterinary assistant and researcher. She began her work in veterinary medicine in 2014 at a small practice in East Tennessee. She has a B.S. in Biology as well as a Master’s degree in Microbiology from East Tennessee State University. Her undergraduate and graduate research focused on Lavengel®, exploring its efficacy and mechanism of action against common bacterial species.

Tasha’s interests focus on natural antimicrobial options and exploring novel compounds to combat antibiotic resistance. She continues to work in small animal emergency and critical care medicine. She spends her free time with her husband and three furry babies in their East Tennessee home.