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How long can a dog live after being diagnosed with cancer?

When our Corpus Christi vets have the sad task of diagnosing cancer in a dog, the owner's first question is typically - how long can my dog live with cancer? Today, our vets explain why that's such a difficult question to answer, even with today's advanced diagnostics and treatments.

Cancer in Dogs

Dogs are susceptible to a variety of cancers, just like humans. These cancers vary in terms of their rate of growth and spread, treatability, and the life expectancy of dogs diagnosed with a specific type of cancer.

Moreover, various factors, such as the breed, age, and overall health of your dog, can significantly influence their chances of survival after cancer diagnosis.

Types of Cancers Commonly Seen in Dogs

Cancer is a significant health concern for dogs, with various types affecting different breeds and age groups. Understanding the common types of dog cancer can help pet owners recognize potential symptoms early and seek appropriate veterinary care.

Here are some of the most frequently encountered cancers in dogs:


Canine lymphoma is one of the most common types of cancer in dogs, which affects the lymphatic system. This cancer can occur in different forms, such as multicentric (affecting multiple lymph nodes), dietary (affecting the digestive system), and mediastinal (affecting the chest). Symptoms of this cancer may include swollen lymph nodes, weight loss, decreased appetite, and lethargy.

How long can a dog live with lymphoma cancer? 

Without treatment, the life expectancy in dogs with lymphoma is one to two months. With treatment, in dogs that feel well, about 80% – 90% of dogs with lymphoma attain a complete remission with an average survival of 12-14 months.

Mammary Gland Tumors

They are common in female dogs, especially those that have not been spayed. These tumors can be benign or malignant and typically occur in older, unspayed females. Regular breast examinations and early detection are crucial for successful treatment.

How long can a dog live with mammary cancer? 

About half of the dogs with malignant tumors also have an excellent prognosis with surgery alone. The remaining 50% of dogs with malignant tumors are at risk for the spread of their tumor. This cancer can lead to illness and poor quality of life, with survival times usually less than one year.


It's a highly aggressive cancer that originates in the blood vessels and often affects the spleen, liver, or heart. Symptoms may include weakness, collapse, abdominal distension, and pale mucous membranes. Unfortunately, hemangiosarcoma is often diagnosed in advanced stages, making treatment challenging.

How long can a dog live with hemangiosarcoma cancer? 

The average survival time with surgery alone is one to three months. The average survival time with surgery and chemotherapy is five to seven months. 90% of dogs are deceased one- year post-diagnosis despite surgery and chemotherapy, with almost 100% mortality two years post-diagnosis.


It's a bone cancer that commonly affects large and giant breeds, such as Great Danes and Saint Bernards. It typically occurs in the long bones of the limbs and can cause lameness, swelling, and pain. Early detection and aggressive treatment, such as amputation followed by chemotherapy, may improve prognosis.

How long can a dog live with osteosarcoma cancer? 

Patients receiving palliative radiation and chemotherapy have an average life expectancy of six months. Amputation with chemotherapy makes the average survival time just a little less than one year, with 20% of dogs still enjoying a good quality of life two years after surgery.


Melanoma cancer is a type of skin cancer that can occur in dogs. It often affects areas with pigmented skin, such as the mouth, lips, and nail beds. While some melanomas are benign, others can be malignant and may metastasize to other organs. Regular skin examinations and prompt evaluation of any suspicious lumps or changes in pigmentation are essential.

How long can a dog live with melanoma cancer? 

The average survival time for this disease is up to about ten months, though dogs can live up to 36 months with immediate surgical removal of the melanoma. The only treatment is surgery because chemotherapy and radiation are not effective. There are four stages of malignant melanoma, each with its own survival time.

Transitional Cell Carcinoma (Bladder Cancer)

It commonly affects the urinary bladder and can cause symptoms such as blood in the urine, increased frequency of urination, and difficulty urinating. While treatment options may include surgery, chemotherapy, and radiation therapy, the prognosis for bladder cancer in dogs is often guarded.

How long can a dog live with bladder cancer?

When it comes to bladder cancer in dogs, the prognosis isn't good. Sadly, the life expectancy for dogs with bladder cancer not receiving treatment is about four to six months, whereas dogs receiving treatment live an average of about six to twelve months.

Mast Cell Tumors

It's a type of skin cancer originating from mast cells, immune cells involved in allergic reactions. These tumors can vary in severity, from benign to highly malignant, and may appear as raised lumps or ulcers on the skin. Early surgical removal and histopathological evaluation are crucial for determining the tumor's grade and planning appropriate treatment.

How long can a dog live with mast cell tumors?

Tumors with high-grade features may still only carry an average survival time of six months, depending on other prognostic factors. Typically, combining surgery with radiation therapy and chemotherapy improves the prognosis.

Adrenal Cancer

There are two types of adrenal cancer: 

  • Adenocarcinoma is a cancerous tumor that develops in the skin or the lining of glands and organs. It can spread to other parts of the body.
  • Pheochromocytoma is a neuroendocrine tumor that originates from neuroendocrine cells.
These are the cells that release hormones in response to stimulation from the nervous system. If pheochromocytoma is malignant, it can spread to the liver, lungs, adjacent blood vessels, or the lymph nodes in the abdominal area. If adrenal carcinoma metastasizes, it typically spreads to the liver, lymph nodes, lungs, and even into the major blood vessels near this organ.
How long can a dog live with adrenal cancer?

Adrenal cortical tumors that can be treated surgically may be cured, but it is more probable that ongoing medical treatment will be necessary. The treatment requires regular monitoring, and life expectancy varies from days to ten years.

How long can a dog live with cancer? 

Predicting the life expectancy of dogs with cancer is a challenging task for veterinarians. This is because few pets with cancer die naturally. When a dog's symptoms become severe, many pet owners choose to euthanize their pet to prevent further suffering. Therefore, the pet owner ultimately decides how long their dog lives following a cancer diagnosis. 

For instance, consider two dogs diagnosed with the same type of cancer. One dog may receive the best available treatment for that specific cancer and live a good quality of life for a year or more. At the same time, the other dog may belong to a family that is unable to pay for such treatment and may need to be euthanized soon after diagnosis. 

It is also important to note that while some cancers are easy to remove surgically if diagnosed early, surgery is not an option for other cancers. Similarly, some cancers may respond well to chemotherapy, while others may not respond at all.

How long can a dog live with cancer without treatment?

It depends on the stage of cancer, dogs who have low-grade oral melanoma (stages one through three) can live more than 18 months, while dogs with high-grade (stage 4) melanoma typically have less than three months.

What Your Vet Can Tell You

Your veterinarian will have the necessary information to tell you about the average lifespan of dogs with a specific type of cancer. However, this number may not be entirely accurate in terms of predicting how long your pet may live. Nevertheless, your vet can provide you with information about the likely progression of your dog's illness and whether any effective treatments are available.

Understandably, finding out that your dog has cancer is a difficult and emotional experience, and you'll want to gather as much accurate information as possible to make the best decisions for your beloved pet. You can trust that your veterinarian has your dog's best interests at heart, as well as yours.

If you're interested in learning more about the signs of cancer in dogs and how it can be detected, we recommend checking out our blog post titled "Cancer in Dogs." Our veterinarians in Corpus Christi share invaluable information on what cancer pain to look out for in your furry friend and effective treatments for managing the pain.

Note: The advice provided in this post is intended for informational purposes and does not constitute medical advice regarding pets. For an accurate diagnosis of your pet's condition, please make an appointment with your vet.

If your dog is showing signs of cancer, contact our Oncology veterinarians in Corpus Christi immediately to book an examination. Our veterinarians can provide you with an accurate diagnosis and recommend the most effective cancer treatment options for your furry friend. 

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Riverside Veterinary Clinic is accepting new patients! Our experienced vets are passionate about the health of Corpus Christi companion animals. Get in touch today to book your pet's first appointment.

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