Do Animals Suffer from Cancer? Facts Every Pet Owner Should Know

Cancer is one of the number one causes of death in humans. But did you know that cats and dogs can also suffer from this disease? In fact, it is the top cause of death in dogs over the age of 10, while about 32% account for deaths in cats over ten years of age.

This post provides a brief overview of cancer in pets, treatment options, and prevention.

What Is Cancer in Pets?

Cancer is the abnormal growth of cells in the body. These cancerous cells can grow and spread to other body parts, damaging healthy tissue. It is not a single illness but a group of diseases with many different forms.

The cause of cancer in pets is largely unknown, but risk factors may increase the likelihood of developing cancer. These include:

  • Old age
  • Certain breeds (e.g., Golden Retrievers, Boxers, Rottweilers)
  • Exposure to carcinogens (e.g., tobacco smoke, chemicals)
  • Obesity
  • Immunosuppression (e.g., from infection, medications)

Stages of Cancer in Pets

The cancer stage is a way to describe how far the disease has progressed. The most common staging system used for cancer in pets is the TNM system, which stands for tumor, node, and metastasis.

  • Tumor. This refers to the primary tumor or the original site where the cancer started.
  • Node. This describes whether the cancer has spread to nearby lymph nodes.
  • Metastasis. This tells whether or not the cancer has spread to distant organs.

Cancer in pets is a serious medical condition that requires expertise. This means that you have to choose a vet clinic or hospital with experience, complete facilities, lab tests, and specialists because not all clinics can provide these. Visit Oceanside Veterinary for comprehensive care of your cats and dogs.

What Are the Signs of Cancer in Pets?

The signs and symptoms of this deadly disease depend on the type and location of the cancer. However, some general signs may indicate your pet has cancer, which include:

  • Loss of appetite
  • Weight loss
  • Lethargy
  • Difficulty breathing
  • Vomiting

Most Common Types of Cancer in Pets

While many types of cancer can affect pets, the most common ones are:

Bone Cancer

This type of cancer is most commonly seen in large breed dogs. When your pet gets bonce cancer, the cancerous cells will attack the healthy cells in their bones. This will cause your pet a lot of pain and make it difficult for them to move around.

Skin Cancer

This is the most common cancer type in dogs and can be either non-melanoma (e.g., basal cell carcinoma) or melanoma (e.g., malignant melanoma). Skin cancers usually appear as lumps or bumps on the skin and can be more prevalent in dogs with lighter-colored fur. Signs and symptoms include:

  • Lumps or bumps on the skin
  • Sores that don’t heal
  • Changes in texture or color of the skin
  • Hair loss
  • Bleeding
  • Dogs with white fur and blue eyes are at an increased risk of developing melanoma.


Lymphoma is a cancer type affecting the lymphatic system – part of the immune system. It includes the lymph nodes, thymus, spleen, and bone marrow. Lymphoma can be either Hodgkin’s disease (affects B-cells) or non-Hodgkin’s lymphoma (affects T-cells). Signs and symptoms include:

  • Enlarged lymph nodes
  • Weight loss
  • Lethargy
  • Loss of appetite
  • Difficulty breathing
  • Vomiting
  • Diarrhea
  • Fever
  • Anemia

Bladder Cancer

Bladder cancer is seen more often in dogs than cats, and signs include blood in the urine, straining to urinate, and urinating more frequently. Bladder cancer affects the urinary bladder, which is the organ that stores urine. When a pet acquires this disease, the cancerous cells will grow and spread in the bladder wall.

Breast Cancer

Breast cancer is most commonly seen in older, intact (not spayed) female dogs. It can also affect male dogs and cats, although this is much less common. Breast cancer usually appears as a lump or mass in the breast tissue and may be accompanied by discharge from the nipples. Signs and symptoms are:

Stomach Cancer

Stomach cancer is relatively rare in both dogs and cats. This affects the stomach lining and can cause vomiting, weight loss, and a decreased appetite. Pets with stomach cancer may also have blood in their stool.

Diagnosis of Cancer in Pets

If you see any signs of cancer in your pet, it’s essential to see a veterinarian as soon as possible. They will perform a physical exam and likely order tests to confirm the diagnosis, such as x-rays, ultrasounds, or biopsies.

This only means that owning a pet comes with responsibilities. In addition to having them vaccinated, you should also take care of their well-being as a whole. For instance, visiting a dog and cat dentist for their oral health is a part of it. Some pet owners even provide alternative treatments like acupuncture for their pets.

Cancer Treatment Options for Pets

The type of treatment your pet receives will depend on the type and stage of cancer. Treatment options are as follows:

  • Surgery. This is often the first treatment recommendation for cancer and may be curative if the tumor is completely removed. The procedure involves removing the tumor and some surrounding healthy tissue.
  • Chemotherapy. This treatment uses drugs to kill cancer cells. It can be administered orally, topically, or intravenously. It can last for several months and may cause side effects, such as vomiting, diarrhea, and hair loss.
  • Radiation therapy. This treatment uses high-energy beams to kill cancer cells. It can be done externally (from a machine outside the body) or internally (by placing radioactive material next to the tumor). Your pet will need to stay at the hospital for this treatment.
  • Targeted therapy. This is a newer type of treatment that uses drugs to target specific mutations found in cancer cells. Targeted therapy can be used in conjunction with other treatments, such as surgery or chemotherapy.
  • Complementary and alternative treatments. These include acupuncture, herbal medicines, and homeopathy. Some pet owners choose to use these treatments alongside conventional therapies, while others use them as standalone treatments.

Prevention of Cancer in Cats and Dogs

Like cancer in humans, the best way to prevent cancer in pets is to have them checked by a veterinarian regularly. This allows for early detection and treatment of any potential problems. You can also help reduce your pet’s risk of cancer by:

  1. Feeding them a healthy diet. A healthy diet for pets includes high-quality, balanced nutrition. For example, dogs should eat 50% protein and 50% vegetables, while an ideal diet for cats is 80% protein and 20% vegetables.
  2. Exercising them regularly. Exercise helps maintain a healthy weight, which can reduce cancer risk. You should consult with your veterinarian before starting any new exercise regimen for your pet.
  3. Avoiding exposure to carcinogens. Carcinogens are substances that can cause cancer. Examples include tobacco smoke, certain chemicals, and radiation. Smoke away from your pet to avoid secondhand smoke if you do.
  4. Maintaining a healthy weight. Obesity is a risk factor for cancer for pets, so it’s vital to keep them at a healthy weight. You can do this by feeding them a healthy diet and providing adequate exercise.
  5. Having them vaccinated against certain cancers (e.g., lymphoma). There are vaccines available for some types of cancer, such as lymphoma. Consult with your veterinarian to see if vaccination is right for your pet.


Animals can suffer from cancer, just like humans. The best way to prevent this fatal disease is to regularly have them checked by a veterinarian and feed them healthy. If you notice any signs of cancer in your pet, it’s crucial to see a reputable animal clinic or hospital, like, as soon as possible for treatment.

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