cancer in cats

What is Cancer in Cats?

What is it?

Cancer in cats is a complex and varied group of diseases that can affect different tissues and organs in the body. It occurs when normal cells mutate and grow uncontrollably, forming abnormal masses or tumors. The causes of cancer in cats are not fully understood, but factors such as genetics, environmental toxins, and viral infections may play a role.

How is it Treated?

The treatment of cancer in cats depends on the type, location, and stage of the disease and may include surgery, chemotherapy, radiation therapy, immunotherapy, or palliative care. Treatment is individualized and requires ongoing maintenance and monitoring by a veterinarian. Early detection and treatment can improve the chances of a successful outcome.

Breed Predispositions

Siamese Abyssinian Persian Burmese Ragdoll


It was during a routine grooming session that Sarah first discovered a small lump on her beloved Abyssinian cat, Max. Worried about the mysterious growth, she immediately scheduled an appointment with her veterinarian. After a series of tests and a biopsy, Sarah received the heart-wrenching news: Max had cancer. In this blog post, we will explore the complex world of cancer in cats

Cancer, a disease where cells grow out of control and divide excessively, can lead to the formation of malignant tumors when cells multiply too rapidly. Individual cats are predisposed to developing specific kinds of cancer due to genetic factors, contributing to an increased risk in some breeds.

Among the various cancer cases in felines, one of the most prevalent is mammary carcinoma, commonly known as breast cancer. However, cancers that can affect cats are not limited to this. Other notable types include squamous cell carcinoma, fibrosarcoma, Mastocytoma, melanoma, lymphoma, leukemia, and plasmacytoma, among others.

Early diagnosis is crucial in managing cancer in cats, as it can significantly improve the chances of remission. Consequently, it’s essential to monitor any changes in your cat’s health and seek veterinary consultation when needed, as affected cats might require immediate attention.

Types of Cancer in Cats

Cats are susceptible to various forms of cancer, some of which bear similarities to those observed in humans. Recognizing these types can empower pet owners to identify symptoms early and seek immediate medical attention.


Lymphoma, one of the most common forms of cancer, significantly affects cats, directly correlating to the feline leukemia virus (FeLV). It impairs lymphocytes, a type of white blood cell, instigating unchecked cell growth and tumor formation. Lymphoma predominantly affects the cat’s lymph nodes, liver, kidneys, intestines, or chest, manifesting symptoms such as weight loss, reduced appetite, vomiting, and diarrhea. In advanced stages, it may induce difficulty breathing.

Squamous Cell Carcinoma

Squamous cell carcinoma (SCC), synonymous with skin cancer in cats, chiefly targets the skin and the oral cavity, with the latter often referred to as mouth cancer. Light-colored or white cats exposed to sunlight are highly vulnerable to SCC, which can result in persistent sores around the face, ears, and mouth. Oral SCC may lead to difficulties in eating, excessive drooling, and unpleasant breath.

Mammary Gland Tumors

Like breast cancer in humans, mammary gland tumors rank third in cats’ list of most common cancers. This form of cancer predominantly affects female cats that either have not been spayed or were spayed post two years of age. Detectable lumps in the breast tissue are the primary indicators of this tumor, with changes in appetite and behavior marking additional symptoms.


Fibrosarcoma, a malignant form of cancer originating from connective tissues, can develop anywhere in a cat’s body, although it’s frequently found on the skin. This aggressive form of cancer often necessitates comprehensive surgical intervention, occasionally coupled with radiation therapy. Symptoms include a palpable growing mass, discomfort, or pain.

Mast Cell Tumors

Mast cell tumors develop from an immune cell named the mast cell. In cats, these tumors generally affect the skin but can also manifest in the spleen, liver, or gastrointestinal tract, contributing to intestinal cancer. Symptoms fluctuate greatly depending on the tumor location, including skin lesions, gastrointestinal complications, or overall uneasiness.

cancer in cats


Osteosarcoma, a rare but aggressive form of bone cancer in cats, primarily targets older cats, although it isn’t exclusive to this age group. It forms within the bone and can compromise bone integrity, potentially leading to fractures.


Feline leukemia, triggered by the feline leukemia virus (FeLV), can culminate in various forms of cancer and immunodeficiency, making the cat more susceptible to other infections. Outdoor cats are particularly at risk. Symptoms include anemia, lethargy, and gradual weight loss.

Lung Cancer

While lung cancer is relatively uncommon in cats, it can originate in the lungs (primary lung cancer) or metastasize from another part of the body (secondary lung cancer). This form of cancer generally affects older cats and is often linked with exposure to secondhand smoke. Symptoms can be elusive but may include coughing, breathing difficulties, and lethargy.

Oral Melanoma

Oral melanoma in cats is a type of cancer that originates in the cells that produce melanin, the pigment that gives color to the skin, hair, and eyes. While it is less common than squamous cell carcinoma, it can be more aggressive and tend to spread to other parts of the body. This cancer typically presents as a dark mass in the cat’s mouth but may not be noticed until it has grown large or spread to other areas.

Pancreatic Cancer

Pancreatic cancer in cats is rare, but it can be challenging to treat when it does occur. This cancer type affects the pancreas, an organ vital for digestion and insulin production. Symptoms are often nonspecific and can include weight loss, loss of appetite, and lethargy. Unfortunately, this type of cancer is often quite advanced before diagnosis, complicating treatment efforts.

Causes of Cancer in Cats

The occurrence of cancer in cats can be attributed to several factors:

Genetic Predispositions

Certain cat breeds or genetic lines may inherently be more prone to developing specific types of cancers. For instance, due to genetic factors, Siamese cats possess a heightened predisposition to develop skin cancer types, including squamous cell carcinoma.

Viral Infections

The Feline Leukemia Virus (FeLV) and Feline Immunodeficiency Virus (FIV) are major contributors to increased cancer risk. FeLV can trigger lymphosarcoma, a cancer affecting the bone marrow’s lymphoid tissues. Although FIV primarily leads to immunosuppression, it can augment susceptibility to various cancer types.

Environmental Influences

Exposure to certain environmental elements, including specific chemicals or toxins, can escalate a cat’s risk of developing cancer. For example, cats subjected to secondhand tobacco smoke are at a higher risk of developing malignant lymphoma and lung cancer. Certain insecticides and pesticides also present a potential cancer risk.

diagnosis of cancer in cats

Age Factor

Like humans, the probability of developing cancer in cats increases with age. As cats age, they accumulate more genetic mutations, potentially leading to cancer-related abnormal cell growth. Consequently, an older cat is more likely to develop lymphoma and other types of cancer.

Additionally, research suggests that cats spayed at a young age may have a reduced risk of developing certain types of cancer, emphasizing the complex interaction between genetic, environmental, and lifestyle factors in cancer development.

Symptoms of Cancer in Cats

Cancer symptoms in cats can vary significantly depending on the type and location of the cancer. However, a few common clinical signs might indicate your feline companion could be dealing with this disease. Here are some of the symptoms of different forms of cancer in cats:

  • Reduced Appetite: A cat with cancer may show a decreased interest in food, leading to noticeable weight loss.
  • Weight Loss: Even if the cat continues to eat a normal diet, it may lose weight, often rapidly.
  • Lumps or Swellings: Any unusual lumps, bumps, or swollen areas, especially those that continue to grow or change shape, could indicate a tumor. This could include an enlarged lymph node, often a sign of systemic illness.
  • Non-healing Sores: Wounds or sores that don’t heal despite appropriate treatment can also indicate an underlying disease, including cancer.
  • Abnormal Discharges: Any abnormal discharge, such as blood, pus, or other unusual substances from any body opening, should be a cause for concern.
  • Difficulty with Normal Functions: If a cat has cancer, it may have trouble breathing, urinating, or defecating due to tumors affecting these bodily functions.
  • Unexplained Bleeding: Any unexplained bleeding, either externally or internally (such as in the urine or stool), can be a symptom of cancer.
  • Persistent Digestive Issues: Persistent or recurrent vomiting or diarrhea can be a sign of gastrointestinal cancers, among other health issues.
  • Behavioral Changes: Changes in behavior, such as increased lethargy, decreased activity, or other unexplained changes, can often be one of the first signs that a cat is not feeling well. This includes cats that get cancer; they may not show specific signs of illness until the disease has progressed.

Remember, these symptoms can also be associated with other health issues, not cancer. Therefore, it’s always important to seek veterinary advice if your cat displays unusual signs or symptoms.

If Your Feline Has Cancer, What Should You Do?

If your cat has been diagnosed with cancer, staying calm and gathering as much information as possible is crucial. Understand the type of cancer, its stage, and available treatment options. If your primary vet is not an oncology specialist, consider consulting with a veterinary oncologist for expert advice on treatment strategies, potential side effects, and prognosis. Treatment options may include surgery, chemotherapy, radiation therapy, or immunotherapy, depending on the cancer type and stage.

Always keep your cat’s quality of life at the forefront of any decisions. Consider the impact of treatments on their well-being and daily life, and understand when it might be time to shift from curative efforts to palliative care or humane euthanasia. As you navigate this challenging time, closely monitor your cat’s behavior, appetite, and overall health, seeking veterinary advice if you notice any concerning changes. It’s also important to take care of yourself during this process; dealing with a pet’s illness can be emotionally taxing, and seeking support from friends, family, or pet loss support groups can be helpful.

Diagnosis of Cancer in Cats

Diagnosing cancer in a feline friend involves several steps that allow veterinarians to understand if and what type of cancer a cat might have. These steps include a physical exam, diagnostic imaging, biopsies, and blood tests.

Physical Examination

During a physical examination, your veterinarian may identify physical anomalies that may suggest the presence of cancer, such as an unusual lump, mass, or even changes in the oral cavity indicative of conditions like oral squamous cell carcinoma. Weight loss, alterations in gum color, or a diminished body condition could also signal underlying health issues.

symptoms of cancer in cats

Diagnostic Imaging

Diagnostic imaging plays a crucial role in visualizing the possible tumor. The growth’s size, location, and characteristics can be ascertained through imaging techniques such as X-rays and ultrasounds. For instance, an X-ray can reveal a mass in the lungs or bone structure, while an ultrasound may offer insights into the health of internal organs like the liver and kidneys. These techniques can also help detect issues like feline mammary tumors in the mammary gland, a common site of cancer in cats.


A biopsy, which involves taking a small tissue sample from the suspected tumor, is often required to confirm a cancer diagnosis. This sample, studied under a microscope, can verify the presence of cancer and provide information about its type and grade.

Blood Tests

Although blood tests can’t diagnose cancer independently, they give valuable information about a cat’s overall health and the presence of conditions often associated with cancer, like inflammation, infection, or anemia. The type of blood cells affected can also hint at the nature of the disease.

As cats live longer due to improved veterinary care, the incidence of diseases associated with old age, like cancer, is increasing. Consequently, regular veterinary check-ups are even more crucial for early diagnosis and effective treatment.

Treatment Options for Cancer in Cats

Your vet may suggest various treatment strategies once your cat has been diagnosed with cancer. The optimal course of treatment will be influenced by the type of cancer your cat is facing, its progression stage, and your cat’s overall health condition.

Early Stage Cancer

At this stage, cancers are generally localized, implying they have not spread beyond their initial site.

  • Surgery

For many early-stage cancers, surgical removal is the primary treatment method. The aim is to excise the tumor and any neighboring lymph nodes containing cancer cells. The success of surgical treatment is contingent on factors such as the cancer type, location, and the individual cat’s overall health.

  • Radiation Therapy

Radiation therapy, including potential laser therapy, might be an appropriate alternative for certain types of cancer that are localized but not easily amenable to surgery—like those located in the brain or near vital organs. This technique can often shrink the tumor, affecting surrounding tissue minimally and potentially delaying the disease’s progression.

Intermediate Stage Cancer

Intermediate-stage cancers may have started to invade local tissues or lymph nodes.

  • Chemotherapy

Chemotherapy, combined with surgery, is often used for intermediate-stage cancer. This treatment method can shrink tumors before surgery, eradicate remaining cancer cells post-surgery, or serve as the primary treatment when surgical intervention isn’t feasible. Interestingly, cats tolerate chemotherapy relatively well, with common side effects such as skin irritation and hair loss being less prevalent than in humans.

  • Targeted Therapy

Targeted therapies are newer medications designed to directly attack cancer cells, often causing fewer side effects than traditional chemotherapy. These therapies can be considered for specific cancer types with certain genetic mutations.

Advanced Stage Cancer

At this stage, cancers typically have metastasized to other organs.

  • Palliative Care

At this advanced stage, treatment aims to maintain the quality of life rather than cure the cancer. This can involve pain management, nutritional support focusing on proper cat nutrition, and treatments to control symptoms like nausea or difficulty breathing.

  • Immunotherapy

Immunotherapy, which stimulates the body’s immune system to combat cancer, can be a viable option for certain advanced cancers.

  • Clinical Trials

Enrolling in a clinical trial may be a potential opportunity for cats with advanced-stage cancer. Clinical trials provide access to new and experimental treatments not yet widely available.

It’s important to remember that each cat’s situation is unique and can influence the choice of treatment. Moreover, the choice will depend on the cancer type and stage, the cat’s overall health, and the owner’s preferences and financial considerations. Certain cancers can be difficult to treat, so it’s crucial to thoroughly discuss with a veterinary oncologist to understand all available options and make an informed decision about your cat’s cancer and treatment plan.

Prevention for Cancer in Cats

While it’s impossible to eliminate the risk of cancer in cats, there are several strategies that pet owners can adopt to reduce their feline’s risk:

  1. Spaying/Neutering: Spaying female cats before their first heat cycle can significantly reduce the risk of mammary cancer. Neutering male cats eliminates the risk of testicular cancer.
  2. Vaccinations: Keeping your cat’s vaccinations up to date, especially the Feline Leukemia Virus (FeLV) and Feline Immunodeficiency Virus (FIV) vaccines, can help prevent cancers associated with these viruses.
  3. Healthy Diet: Feed your cat a balanced, nutritious diet to maintain a healthy weight. Obesity can increase the risk of certain types of cancer.
  4. Regular Vet Check-ups: Regular veterinary examinations can help detect cancer in its early stages when it is most treatable. The vet can also advise on preventative care and monitor your cat’s health.
  5. Limit Exposure to Carcinogens: Limit your cat’s exposure to known carcinogens such as tobacco smoke, certain pesticides, and excessive sunlight (which can cause skin cancer, particularly in white cats).
  6. Dental Care: Regular dental care can prevent oral cancers. Talk to your vet about the best methods of dental care for your cat.
  7. Regular Exercise: Regular exercise helps maintain a healthy weight and boosts overall health, potentially reducing cancer risk.

Remember, even with the best preventative care, there is always a risk that a cat may develop cancer. The best approach is to combine a healthy lifestyle with regular vet check-ups for early detection and treatment.

Frequently Asked Questions

The lifespan of cats with cancer can vary depending on the type, stage, and aggressiveness of the cancer, as well as the effectiveness of treatment. Some cats may live for months to a few years with appropriate care and treatment.

The cost of treating cat cancer can vary significantly depending on the type of cancer, stage, treatment options, and geographical location. Treatment costs may include diagnostic tests, surgery, chemotherapy, radiation therapy, medications, and follow-up care. It’s best to consult a veterinarian to discuss treatment options and associated costs.

The speed at which cancer spreads in cats can vary depending on the type of cancer. Some cancers may spread quickly, while others progress more slowly. Early detection and treatment can help slow down or prevent the spread of cancer.

The cost of a cat biopsy can vary depending on various factors, such as the location of the biopsy, the type of biopsy performed, and the veterinary clinic. Biopsy costs typically include the procedure, laboratory fees for analyzing the biopsy sample, and any necessary anesthesia or sedation.

The life expectancy of a cat with cancer depends on several factors, including the type and stage of cancer, the effectiveness of treatment, the cat’s overall health, and individual variations. Working closely with a veterinarian is important to determine the prognosis and develop an appropriate treatment plan.

The curability of cat cancer depends on the specific type and stage. Some types of cancer in cats can be curable, while others may be manageable but not curable. The prognosis and treatment options vary, and it’s crucial to consult with a veterinarian for an accurate assessment and to discuss treatment possibilities.

Tumors in cats can cause varying levels of pain depending on their location, size, and characteristics. Some tumors may be painful, while others may not cause noticeable discomfort. Regularly monitoring your cat’s behavior, appetite, and signs of distress can help assess its comfort level, and pain management options can be discussed with a veterinarian.

Providing a comfortable environment for a cat with cancer involves ensuring a quiet and safe space, maintaining proper nutrition, managing pain or discomfort with appropriate medications, providing gentle and supportive care, and offering emotional support through regular interaction and attention.

While cancer can be a serious and life-threatening condition, it is not necessarily a death sentence for cats. The prognosis and outcome depend on various factors, such as the type of cancer, stage, treatment options, and the individual cat’s response. Early detection, appropriate treatment, and supportive care can significantly improve a cat’s quality of life and extend its lifespan.

The decision to treat a cat with cancer is a personal one that should be made in consultation with a veterinarian. Factors to consider include the type of cancer, treatment options, potential benefits, risks, prognosis, and the cat’s overall well-being. Discussing the potential outcomes and quality of life with the veterinarian is important to make an informed decision.

Survival rates for cats with cancer can vary depending on the type of cancer, stage, treatment, and individual factors. Some types of cancer have higher survival rates, especially if caught early and treated appropriately. It’s best to consult a veterinarian for specific survival rate information related to your cat’s type of cancer.

One of the most common cancers in cats is lymphoma, which affects the lymphatic system. Other common types include squamous cell carcinoma (mouth and skin cancer), mammary gland tumors, and fibrosarcoma (soft tissue sarcoma). However, the prevalence of different types of cancer can vary depending on geographic location and other factors.

Cats can develop cancer at any age, but certain types of cancer are more common in older cats. The risk of developing cancer generally increases with age, and cats over ten are more prone to cancer. However, some cancers can also affect younger cats.

The effects of cancer in cats can vary depending on the type and stage of cancer. Common effects may include weight loss, changes in appetite, lethargy, difficulty breathing, changes in behavior, and the development of visible tumors. The specific effects depend on the affected organ or system and may vary from cat to cat.

The exact causes of stomach cancer in cats are often unknown. However, factors such as genetic predisposition, environmental factors, exposure to certain carcinogens, chronic inflammation, and diet have been suggested to play a role. Further research is needed to fully understand the causes of stomach cancer in cats.

Mouth cancer in cats can be caused by various factors, including chronic inflammation, exposure to tobacco smoke, dental disease, viral infections (e.g., feline leukemia virus), and genetic predisposition. Regular dental care and veterinary check-ups can help identify and address potential risk factors.

Hereditary factors can contribute to the development of cancer in cats. Certain breeds may have a higher predisposition to specific types of cancer due to genetic factors. However, it’s important to note that not all cases of cat cancer are solely due to hereditary factors, and environmental factors can also play a significant role.

Detecting cat cancer usually involves a combination of physical examination, diagnostic tests (e.g., blood tests, imaging studies), and sometimes biopsies or other tissue sampling methods. Early detection is key to improving treatment options and outcomes.

Mouth cancer in cats can cause bleeding, especially as the tumor progresses and invades surrounding tissues. Bleeding may be visible as blood in saliva, food, or objects the cat chews on. If you notice unexplained bleeding or oral abnormalities, it’s important to consult a veterinarian for an evaluation.

Fever is not a common symptom of cat cancer unless it is associated with an infection or inflammatory response related to cancer. However, fever can occur due to certain types of cancer or cancer treatments. If your cat has a fever or other concerning symptoms, it’s best to consult a veterinarian for an evaluation.

Environmental factors such as exposure to certain chemicals, pollutants, tobacco smoke, and other carcinogens may contribute to the development of cancer in cats. Minimizing exposure to such substances and providing a safe and clean living environment can help reduce the potential risks.

The duration of cancer treatments in cats can vary depending on the type of cancer, treatment protocols, and the individual response. Some treatments, such as surgery or a few chemotherapy sessions, may be relatively short, while others may require more prolonged treatment spanning several weeks to months.

Certain cat breeds have been found to have a higher predisposition to specific types of cancer. For example, Siamese cats have an increased risk of developing mammary gland tumors, while Persians are more prone to certain types of skin cancer. However, it’s important to note that cancer can occur in any cat breed.

 Veterinary medicine continues to advance in feline cancer therapies, including surgical techniques, radiation therapy, and chemotherapy protocols. While not all cancers can be cured, treatment options and outcomes continually improve, leading to a better quality of life and extended survival for many cats with cancer.

The underlying causes of elevated cancer rates in cats are multifactorial and complex. Factors such as genetics, environmental exposures, lifestyle, diet, and individual susceptibility all contribute. Ongoing research aims to understand these factors better to develop preventive measures and improved treatment options.

Disclaimer: The information provided on this veterinary website is intended for general educational purposes only and should not be considered as a substitute for professional veterinary advice, diagnosis, or treatment. Always consult a licensed veterinarian for any concerns or questions regarding the health and well-being of your pet. This website does not claim to cover every possible situation or provide exhaustive knowledge on the subjects presented. The owners and contributors of this website are not responsible for any harm or loss that may result from the use or misuse of the information provided herein.

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