Cat Cancer: Understanding Types, Symptoms, and Treatment Options

Cancer is a serious health concern affecting not only humans but also our feline companions. Just like in humans, Cat Cancer occurs when cells in a cat’s body grow and divide uncontrollably, leading to tumors. Understanding cat cancer is crucial for pet owners to ensure early detection and provide the best possible care for their beloved cats.

What is Cat Cancer?

In essence, cancer in cats mirrors the disease in humans. A cat’s body is composed of millions of cells, each with specific functions, including energy production, DNA storage, and fighting infections. Normally, these cells undergo a regulated cycle of growth, division, and death, replaced by new, healthy cells. However, sometimes this process goes awry. Cells can become damaged, yet instead of dying, they continue to multiply uncontrollably. This abnormal proliferation of cells can result in the formation of tumors, which may be benign (non-cancerous) or malignant (cancerous). Malignant tumors are what we refer to as cancer, and they pose a significant threat to a cat’s health.

Approximately 6 million cats in the US are diagnosed with cancer annually. Alarmingly, a significant proportion of tumors in cats, ranging from 53% to 83%, are malignant. The prognosis and survival rate for cats with cancer are highly variable, depending on several critical factors: the specific type of cancer, whether the cancer has spread to other parts of the body (metastasis), and the cat’s overall health condition.

Types of Cancer in Cats: A Comprehensive Overview

Cats are susceptible to a wide range of cancers. Here’s a detailed look at some of the most common types:

Lymphoma: This is the most prevalent type of cancer diagnosed in cats. Lymphoma affects lymphocytes, a type of white blood cell crucial for the immune system. These cells are found throughout the body in lymphoid tissue, making lymphoma a systemic disease. Common sites affected in cats include the gastrointestinal (GI) tract, kidneys, and lymph nodes.
Mast Cell Tumors (Mastocytomas): These tumors originate from mast cells, which are produced in the bone marrow and circulate throughout the body, playing a role in allergic responses. In cats, mast cell tumors most frequently develop in the skin or spleen.
Leiomyosarcoma: While rare, leiomyosarcoma is a painful form of soft tissue sarcoma that affects the smooth muscles of the stomach and intestines in cats.
Fibrosarcoma: This cancer affects soft tissues such as muscle and connective tissues. Fibrosarcomas in cats are typically slow-spreading but can be locally aggressive, meaning they invade surrounding tissues.
Mammary Tumors: These tumors develop in the tissue surrounding a cat’s mammary glands (teats). Mammary cancer in cats is often aggressive and tends to metastasize to regional lymph nodes and the lungs.
Osteosarcoma: This is a type of bone cancer that affects the skeletal system of cats. Osteosarcoma is known for being locally aggressive and causing significant pain.
Ceruminous Gland Adenocarcinoma: This less common cancer arises from the sweat glands in a cat’s ear canal.
Melanoma: Melanomas are tumors of melanocytes, the cells that produce pigment. In cats, melanomas often appear as isolated, raised masses that may bleed. They can occur in various locations, including the mouth, skin, and eyes.
Myeloproliferative Neoplasm: This is a category of blood cancers that originate in the bone marrow, affecting the production of blood cells.
Squamous Cell Carcinoma (SCC): SCC is the most common type of skin cancer in cats. It is characterized by rapid growth and can be particularly aggressive.
Hemangiosarcoma: This is a fast-growing, malignant tumor that develops from the cells lining blood vessels. Hemangiosarcoma can lead to internal bleeding due to the fragile nature of the tumor vessels.
Transitional Cell Carcinoma (TCC): TCC is a tumor that develops in the bladder of cats. It is locally aggressive and can cause urinary issues.
Uterine Cancer: Tumors of the uterus are rare in cats and typically seen in middle-aged to older cats. Treatment usually involves surgical removal of the uterus and ovaries, known as an ovariohysterectomy or spay.
Ovarian Tumors: Ovarian tumors are also uncommon in cats, but they have a higher tendency to metastasize. Often, the ovaries can be a site of metastasis from cancers originating elsewhere in the body. Treatment, similar to uterine cancer, involves surgical removal of the ovaries.

Alt text: A veterinarian gently examines a tabby cat lying comfortably on an examination table in a brightly lit clinic setting.

Recognizing Cat Cancer Symptoms

The symptoms of cancer in cats are diverse and often depend on the type and location of the tumor. It’s important to be vigilant and watch for any changes in your cat’s health. Common signs can include:

Unexplained weight loss: Significant weight loss without dietary changes.
Changes in appetite: Loss of appetite or difficulty eating.
Lethargy and weakness: Reduced energy levels and unusual tiredness.
Vomiting or diarrhea: Persistent digestive issues.
Difficulty breathing or coughing: Respiratory problems.
Increased thirst or urination: Changes in drinking and urination habits.
Lumps or bumps: New or growing masses under the skin.
Non-healing sores: Wounds that don’t heal properly.
Changes in behavior: Unusual aggression, hiding, or other behavioral shifts.
Pain or lameness: Signs of discomfort or difficulty moving.

It is important to note that these symptoms can also be indicative of other feline illnesses. However, if you observe any of these signs, it is crucial to consult your veterinarian for a thorough examination.

Potential Causes of Cancer in Cats

While the exact causes of cancer in cats are not always fully understood, several factors are known to increase the risk. These include:

Age: The risk of cancer generally increases with age in cats, although certain types of cancer may be more common in younger cats.
Genetics: Some breeds may be predisposed to certain types of cancer, suggesting a genetic component.
Environmental factors: Exposure to certain environmental toxins, such as asbestos and tobacco smoke, can elevate cancer risk. Similarly, excessive exposure to ultraviolet (UV) radiation from sunlight is a risk factor for skin cancers like squamous cell carcinoma.
Viral infections: Certain viral infections, such as feline leukemia virus (FeLV) and feline immunodeficiency virus (FIV), have been linked to an increased risk of lymphoma and other cancers in cats.

Diagnosing Cancer in Cats: Veterinary Procedures

Diagnosing cancer in cats requires a systematic approach by your veterinarian. The process typically begins with:

Medical History and Physical Examination: Your vet will start by taking a detailed history of your cat’s health, including any symptoms you’ve observed. Providing a record of symptoms and even photos of any visible masses can be helpful. A thorough physical examination is essential to assess your cat’s overall health and identify any abnormalities.
Blood and Urine Tests: These routine tests provide valuable information about your cat’s organ function and overall health, which can help narrow down potential diagnoses.
Imaging Tests: If cancer is suspected, various imaging techniques are crucial for visualizing internal organs and detecting tumors. Common imaging modalities include:
- X-rays (Radiographs): X-rays are useful for examining the chest, abdomen, and bones. They can help identify masses, changes in organ size, or bone abnormalities.
- Ultrasound: Ultrasound provides real-time images of internal organs using sound waves. It is particularly helpful for examining soft tissues and abdominal organs.
- Endoscopy: This procedure involves inserting a small camera into the mouth or rectum to visualize the stomach, intestines, or other internal areas.
- Computed Tomography (CT) Scans: CT scans use X-rays and computer processing to create detailed cross-sectional images of the body, offering high resolution and contrast.
- Magnetic Resonance Imaging (MRI): MRI provides even more detailed images, particularly of soft tissues, without using radiation. MRI is excellent for visualizing the brain, spinal cord, and other soft tissue structures.

Alt text: A veterinarian in a blue scrub top performs an ultrasound on a ginger cat lying on its side on a padded table.

While imaging can reveal the presence of a tumor, it cannot definitively diagnose the type of cancer. To obtain a definitive diagnosis, a sample of the tumor is necessary for microscopic examination. This is typically achieved through:

Fine Needle Aspirate (FNA): An FNA involves inserting a thin needle into the tumor to collect a sample of cells using a syringe. The cells are then examined under a microscope by a veterinary pathologist.
Biopsy: A biopsy involves surgically removing a small piece of the tumor tissue. Biopsies provide a larger tissue sample and generally offer a more accurate diagnosis and can help predict the tumor’s behavior (grade and prognosis).

In some cases, cats may not be healthy enough to undergo sedation or anesthesia required for advanced imaging or biopsies. In these situations, less invasive diagnostic methods may be prioritized, and treatment decisions may be based on the available information and the cat’s overall condition.

Cat Cancer Treatment Options

The approach to treating cat cancer is multifaceted and tailored to the individual cat, considering factors such as:

Type of cancer: Different cancers respond differently to various treatments.
Cancer stage: The extent to which the cancer has spread (staging) is a critical factor in treatment planning.
Tumor location and size: The location and size of the tumor can influence treatment options and surgical feasibility.
Pre-existing health conditions: Underlying health issues can impact a cat’s ability to tolerate certain treatments.

Your veterinary oncology team will develop the most appropriate treatment plan, which may involve one or more of the following modalities:

Surgery: Surgical removal is a primary treatment option for many types of cancer, especially tumors that are accessible and localized. Surgery aims to remove the entire tumor and, when possible, a margin of healthy tissue around it to minimize the risk of recurrence.
Chemotherapy: Chemotherapy involves using drugs to kill cancer cells or slow their growth. It is often administered intravenously or orally. Chemotherapy is particularly useful for cancers that have spread or are likely to spread, such as lymphoma.
Radiation Therapy: Radiation therapy uses high-energy rays to target and destroy cancer cells. It is a localized treatment and can be effective for tumors that cannot be surgically removed or for microscopic disease remaining after surgery.
Immunotherapy: Immunotherapy is a newer approach that aims to boost the cat’s own immune system to fight cancer cells. While still relatively new in feline oncology, immunotherapy holds promise for certain types of cancer.
Photodynamic Therapy: This therapy combines light and light-sensitive substances to destroy cancerous tissue. A light-activated drug is administered, which selectively accumulates in cancer cells. When exposed to a specific wavelength of light, the drug becomes activated and destroys the cancer cells.

Often, a combination of treatments is employed to achieve the best outcome. For instance, surgery to remove a tumor followed by chemotherapy may be recommended to eliminate any remaining cancer cells and reduce the risk of recurrence.

In cases where cancer is advanced, or the cat is not a good candidate for aggressive treatments, palliative care becomes essential. Palliative care focuses on managing pain and symptoms, improving quality of life, and providing comfort. This may include pain medication, anti-inflammatory drugs, nutritional support, fluid therapy, and blood transfusions as needed.

Recovery and Long-Term Management After Cat Cancer Treatment

Recovery and management after cancer treatment are crucial for ensuring your cat’s well-being. The recovery process and timeline will vary depending on the type of treatment, the cat’s overall health, and individual factors. Your veterinarian will provide detailed post-treatment instructions. Key aspects of recovery and management include:

Creating a Calm and Comfortable Environment: Provide a quiet, enclosed space with easy access to fresh water, food, a comfortable bed, and a litter box.
Close Monitoring: Carefully observe your cat for any signs of complications, pain, or changes in appetite, energy level, or behavior.
Assisted Care: Offer assistance with grooming, eating, or mobility as needed, especially if your cat is weak or recovering from surgery.
Adhering to Veterinary Guidelines: Strictly follow all instructions provided by your veterinarian regarding medications, diet, wound care, and activity restrictions.
Follow-up Appointments: Prioritize all scheduled follow-up appointments. These appointments are essential for monitoring your cat’s progress, detecting any recurrence of cancer, and adjusting the management plan as needed.

Alt text: A ginger cat rests comfortably in a soft cat bed positioned near a window, gazing peacefully outside.

It’s important to remember that even if a cat is not a candidate for curative cancer treatment, they can still maintain a good quality of life with supportive care. However, if a cat’s quality of life deteriorates significantly and they are experiencing persistent pain or suffering, humane euthanasia may be the most compassionate option. Your veterinarian can provide guidance and support in making this difficult decision, ensuring your cat’s comfort and dignity.

Preventing Cancer in Cats: Risk Reduction Strategies

While not all cancers in cats are preventable, there are steps you can take to minimize your cat’s overall risk:

Reduce Exposure to Toxins: Minimize your cat’s exposure to indoor toxins such as asbestos, tobacco smoke, and certain chemicals. Ensure proper ventilation when using household cleaning products.
Limit UV Light Exposure: Reduce prolonged sun exposure, especially during peak hours, to decrease the risk of skin cancer, particularly for cats with white or light-colored fur.
Regular Veterinary Checkups: Prioritize annual veterinary wellness exams for young adult cats and biannual exams for cats older than 8 years. Regular checkups allow for early detection of potential health issues, including cancer, when treatment may be more effective.

Common Questions About Cat Cancer (FAQs)

How long can a cat live with cancer?

The lifespan of a cat diagnosed with cancer is highly variable. It depends on numerous factors, including the type of cancer, stage at diagnosis, treatment received, and the cat’s overall health. Some cats may only survive for a few days or weeks after diagnosis, while others, particularly with early detection and effective treatment, can live for months or even years with a good quality of life.

References

Corp-Minamiji C. Cancer is a Cellular Delinquent. Veterinary Partner. March 9, 2015.

Warning signs of cancer. Cornell University College of Veterinary Medicine. Accessed February 18, 2024.