A watercolor painting of a cat on a bed, highlighting its orange fur.

What is Melanoma in Cats?

What is it?

Melanoma in cats is a type of cancer arising from melanocytes, which produce pigment. It can occur in various body parts, including the skin, mouth, and eyes. Melanomas can be either benign or malignant and are more commonly found in older cats.

How is it Treated?

Treatment for melanoma in cats typically involves surgical removal of the tumor. Depending on the location and extent of the cancer, additional treatments such as radiation therapy or chemotherapy may also be recommended. In some cases, immunotherapy may boost the cat’s immune system to fight cancer.

Breed Predispositions

There are no known breeds that are predisposed to melanoma in cats. However, age, gender, and immune status may increase the risk of developing melanoma.


Nina had always been an attentive cat owner, keeping a watchful eye on her beloved feline friend, Misty. But when she noticed a dark, pigmented mass on Misty’s ear, she couldn’t help but feel a sense of unease. Deciding to err on the side of caution, Nina took Misty to the veterinarian for a thorough examination. To Nina’s dismay, the veterinarian diagnosed Misty with melanoma, a form of skin cancer that can affect both humans and animals. Overwhelmed by the diagnosis, Nina knew she had to learn more about melanoma in cats in order to provide the best care possible for Misty.

Melanoma in cats is a type of cancer originating from melanocytes, cells responsible for producing the pigment melanin. Melanoma can occur in various locations, including the skin, oral cavity, and eyes. It arises due to certain mechanisms within the body that lead to the uncontrolled growth and proliferation of abnormal melanocytes. Melanoma can present as pigmented or non-pigmented tumors, and its occurrence involves disrupting normal cell growth and division processes. Understanding the occurrence of melanoma helps recognize the condition and seek appropriate veterinary care promptly. 

Types of Melanoma in Cats

Melanoma, a form of skin cancer originating from the melanocytes, or pigment-producing cells, can present itself in multiple forms in cats. Despite being relatively rare in cats compared to dogs and humans, when melanoma develops, it often displays an aggressive nature, especially in oral melanoma. Melanomas can emerge in various locations, including the skin, mouth (oral melanoma), and eyes (ocular melanoma). These melanomas can behave as benign or malignant, depending on their nature.

Benign Melanoma (Melanocytoma)

Melanocytomas, or benign melanomas, are typically less aggressive and tend to stay confined without metastasizing to other body regions. These tumors generally grow at a slow pace and can often be completely eradicated through surgical intervention. The two primary types of benign melanoma, based on their location, are:

  1. Cutaneous Melanocytoma: This type of melanoma appears on the skin as a solitary, distinct, black or dark brown tumor.
  2. Ocular Melanocytoma: This form of melanoma, including limbal and uveal melanoma, emerges in the eye, possibly leading to color alterations in the iris or pupil.
vadrgvet a weak cat lying on the sofa loose watercolor sketch m ff6acab1 ad4d 4315 b07e 255fbd6a542a

Malignant Melanoma

Malignant melanomas display a more aggressive behavior and carry the potential to spread to other parts of the body, such as the lungs and lymph nodes. These forms of melanoma are usually more invasive and carry a less favorable prognosis than benign melanomas. They are also categorized according to their location:

  1. Cutaneous Malignant Melanoma: This skin melanoma can manifest as a quickly expanding black mass, potentially ulcerating and bleeding.
  2. Oral Malignant Melanoma: These oral melanomas are generally aggressive, frequently spreading to the bone and can lead to difficulties eating, drooling, and halitosis.
  3. Ocular Malignant Melanoma: These eye melanomas may impair vision or cause complete blindness, making the eye appear swollen or bloody.
  4. Digital Malignant Melanoma: These melanomas occur on cats’ digits (toes), often associated with discomfort and inflammation.

It’s critical to understand that although cats may have skin cancer like melanoma, it’s less prevalent. If you notice any abnormal growths or changes in your cat, consulting a veterinarian for a thorough examination is always recommended.

Stages of Melanoma

The melanoma stage offers information about the cancer’s degree of spread. Veterinary oncologists utilize the TNM (Tumor, Node, Metastasis) system to stage melanomas. Here’s a simplified explanation:

  • Stage I: The tumor is small and localized, with no metastasis to lymph nodes or distant sites.
  • Stage II: The tumor is larger or has invaded deeper skin layers, but no lymph nodes or distant sites are affected.
  • Stage III: The cancer has metastasized to the nearest lymph node but hasn’t spread to other body parts.
  • Stage IV: The cancer has metastasized to distant sites, such as the lungs or other organs.

The melanoma stage at diagnosis can aid in determining the prognosis and guiding treatment decisions. Cats diagnosed with early-stage melanomas generally have a more favorable prognosis than those with advanced-stage melanomas. However, the prognosis for malignant melanoma in cats, especially oral melanoma, is often poor due to these tumors’ aggressive nature.

Causes of Melanoma in Cats

The precise cause of melanoma, a highly malignant cat skin cancer, remains elusive. However, it is believed to arise due to genetic and environmental influences. Below are some insights into potential causes and risk factors:

Genetic Influences

Genetic factors likely predispose certain cats to melanoma, similar to humans. Such genetic predispositions can trigger cells to mutate and increase uncontrollably, eventually forming tumors.

Sun Exposure

Like humans, exposure to sunlight is a recognized risk factor for skin melanoma in various species. Cats, particularly those with light-colored or white fur and those spending a significant amount of time outdoors, are more prone to sun-induced skin damage and potentially higher risks of developing skin melanomas. However, the correlation between sun exposure and melanoma in cats is less explicit than in humans, especially considering that the leading cause of skin cancer in cats is often oral melanoma, unaffected by sunlight exposure.

Persistent Inflammation or Irritation

Chronic inflammation or irritation in the oral region might contribute to developing oral melanoma in cats. Such irritation could stem from dental disease, tobacco smoke exposure, or other chronic oral conditions.


Melanoma tends to occur more frequently in older cats, as the risk for most cancers amplifies with age.

Viral Infections

Preliminary studies have suggested a potential association between specific viral infections and an elevated risk of melanoma. However, these findings warrant further investigation for confirmation.

Due to the possible genetic elements, preventing melanoma in cats can be a complex task. Nonetheless, measures such as minimizing sun exposure, promoting good oral health, and scheduling routine veterinary check-ups for early detection of changes can be helpful. Skin and intraocular tumors are visible signs your cat might have skin cancer. If you observe any alterations in your cat’s skin, mouth, eyes, or overall behavior, immediate consultation with a vet is crucial.

Symptoms of Melanoma in Cats

The clinical signs of melanoma in cats can fluctuate based on the cancer’s location and severity. Some of the symptoms that may be indicative of this condition include:

  • The presence of unusual growths or lumps on the skin or within the mouth
  • Modifications in color, size, or shape of pre-existing moles
  • Persistent ulcers or sores that fail to heal
  • Challenges while eating or reduced appetite
  • Excessive salivation or unpleasant breath, particularly in the case of oral melanomas
  • Bleeding or discharge from the nose or oral cavity
  • Facial or ocular swelling, often associated with conditions such as feline diffuse iris melanoma or uveal melanoma
  • Decreased activity or lethargy
  • Unexplained weight reduction
  • Difficulty breathing, a symptom of skin cancer potentially indicating that the melanoma has impacted the respiratory system, particularly the lungs

It’s important to note that these clinical signs do not strictly indicate melanoma and could point to various health concerns, including conditions affecting the ciliary body in the eye. A vet consultation is imperative to ascertain the root cause if your cat demonstrates these signs.

Diagnosing Melanoma in Cats

Determining a diagnosis of melanoma in felines necessitates a variety of steps. Clinical evaluation, diagnostic tests, and imaging studies might be employed to verify melanoma’s presence and gauge its progression. Here are some key processes that could play a part:

Physical Assessment

A meticulous physical evaluation forms the first step in diagnosing a cat with melanoma. The vet will look for indicators of a malignant tumor, such as a growth on the cat’s skin or mouth while evaluating the cat’s overall health. If growth is identified, the vet will scrutinize it for signs of malignancy, like alterations in color, shape, size, or ulceration.

Fine Needle Aspiration or Tissue Sampling

The vet might execute a fine needle aspiration (FNA) or a biopsy in dubious growth. During an FNA, cells are extracted from the growth with a slim needle, followed by a microscopic examination. This process often yields useful information regarding the type and possible malignancy of the cells.

A larger tissue sample is obtained for a biopsy by cutting a small part of the growth (incisional biopsy) or the entire growth (excisional biopsy). This sample is then sent to a lab where a pathologist can conduct a comprehensive examination, providing a definitive diagnosis of melanoma.

Imaging Procedures

Imaging procedures like X-rays, abdominal ultrasounds, or CT scans may be employed to assess the extent of the tumor and search for indications of metastatic disease, i.e., cancer spread to other areas. For instance, chest X-rays can disclose if cancer has spread to the lungs, while an abdominal ultrasound can shed light on the health status of the liver and other organs.

Blood Analysis

Blood tests can offer insights into the cat’s overall health, assisting the veterinarian in evaluating the cat’s capacity to handle potential treatments. Some blood tests can also shed light on the body’s response to neoplastic cells or tumors.

Disease Staging

If a diagnosis of melanoma is confirmed, additional tests may be necessary to ascertain the stage of the disease, indicating the extent of cancer spread. This might involve further imaging studies, evaluation of the lymph nodes, and possibly other tests. The stage of cancer significantly impacts the prognosis and the plan for diagnosis and treatment.

While these processes can yield a wealth of information, it’s crucial to remember that each cat is unique, and not all cats will require all these tests. The vet will suggest the most appropriate tests based on the cat’s symptoms, the physical examination, and the initial test results.

Please remember that potential signs of developing skin cancer in cats, like growths on the skin or secondary glaucoma, should not be ignored. Always consult a vet if you notice any changes in your pet’s health.

Treatment Options for Cats with Melanoma

vadrgvet a veterinarian examining a weak cat lying on the table 5c9ab71b cf57 4eab a96e 78c2db86103b

The treatment of melanoma in cats, whether benign or malignant, primarily depends on the body part where it develops, the extent of tumor spread, and the cat’s overall health.

Benign Melanoma

Benign melanomas, or melanocytomas, are often less aggressive and may be completely removed through surgical removal. Sometimes, no treatment is necessary if the tumor does not interfere with the cat’s quality of life and slow growth rate.

Malignant Melanoma

Malignant melanomas are usually more aggressive and can spread to other body parts. These forms of cancer present a more significant challenge, and treatment options include:

  • Surgery

Surgical tumor removal is often the first-line treatment for localized malignant melanomas. For instance, oral tumors may require the removal of part of the jaw. The extent of surgery depends on the location and size of the tumor.

  • Radiation Therapy

Radiation therapy is often used when the melanoma is situated in a challenging location, such as inside the eye, or if the cancer persists even after surgical removal. It can help control the growth of the tumor and alleviate symptoms, but it usually doesn’t cure the cancer.

  • Chemotherapy

If cats develop melanoma that has metastasized or spread to other parts of the body, chemotherapy or radiation may be considered. It may also be used in conjunction with surgery and radiation therapy. However, the response of feline melanoma to this form of cancer treatment is variable.

  • Immunotherapy

Immunotherapy, which involves stimulating the cat’s immune system to fight cancer, is an emerging field in veterinary oncology. While not yet widely available, initial studies show promise for treating malignant forms of cancer, potentially including melanoma.

  • Palliative Care

For cats with advanced-stage melanoma or those not candidates for other treatments, palliative care can help manage symptoms and improve quality of life. This might include pain management, nutritional support, and other supportive measures.

Regardless of the treatment, follow-up care is crucial in managing melanoma in cats. This may include regular physical examinations and monitoring for signs of recurrence or metastasis in the case of malignant melanoma.

As always, the most appropriate treatment plan for a cat with melanoma should be determined in collaboration with a veterinarian or a veterinary oncologist. The cat’s overall health, age, and the potential benefits and risks of each treatment option should be considered.

How to Prevent Feline Melanoma?

While thwarting the development of melanoma in felines can be an arduous task, owing to the multitude of potential causes and contributing factors, there are several strategies that owners can employ to mitigate the risk:

Sun Exposure Management

Even though the association between sun exposure and feline melanoma isn’t as straightforward as in humans, limiting your cat’s exposure to the sun is still beneficial, especially during peak hours. This becomes particularly crucial for light-furred or hairless cats, who might be more prone to sun damage. Offering shaded spaces outdoors and applying sun-blocking films to windows indoors can be helpful.

Routine Vet Consultations

Frequent vet check-ups can facilitate the early detection of melanoma and other cancers when most susceptible to treatment. Your vet can perform comprehensive physical examinations and suggest any appropriate diagnostic tests.

Oral Hygiene

Considering the prevalence of oral melanoma in felines, preserving your cat’s oral health might aid in preventing this disease. Regular teeth brushing, dental diets, and professional dental cleanings can all promote a healthy mouth environment.

Tobacco Smoke Avoidance

Cats exposed to tobacco smoke are at a heightened risk of developing oral cancers, likely due to the carcinogens that settle on their fur and are ingested during grooming. If you smoke, consider quitting or ensuring your cat is not exposed to secondhand smoke.

Healthy Lifestyle

Although there’s no direct link between diet, exercise, and feline melanoma, a healthy lifestyle can bolster overall well-being and a robust immune system. The latter can aid the body in warding off cancerous transformations, particularly invasive melanomas.

Changes Surveillance

Maintain vigilance over your cat’s body and behavior. If you notice any changes, such as new growths, alterations in eating or grooming habits, or anything unusual in your cat’s eye, seek a vet’s advice immediately.

While these strategies can’t assure that your cat won’t develop melanoma – as melanomas are tumors appearing in various body areas, including the skin, mouth, and eyes – they can contribute to a healthier life. If caught early, considering the prognosis, the earlier detection and treatment of melanoma can potentially save your cat’s life.

Research on a melanoma vaccine for cats is currently underway and may provide another avenue to protect your cat from this type of cat skin cancer in the future.

Frequently Asked Questions

Melanoma in cats can vary in appearance depending on its location and stage. In the skin, melanomas may appear as raised, pigmented, or dark-colored lumps or masses. They can be solitary or multiple. Melanomas in the mouth may present as dark, irregularly shaped growths on the gums, lips, or tongue. Melanomas can affect the iris in the eyes, causing changes in pigmentation or the appearance of dark spots or nodules. Not all pigmented masses are melanomas, and a definitive diagnosis can only be made through proper evaluation by a veterinarian, including diagnostic tests and possibly a biopsy.

Cancerous lumps on cats can have varying textures. They can be hard, firm, or soft, depending on the type of cancer, its location, and its growth characteristics. Some cancers, such as fibrosarcomas, may present as firm or solid masses. Others, like lipomas (benign fatty tumors), tend to be soft and easily movable under the skin. However, it is important to note that the texture of a lump alone cannot definitively determine if it is cancerous or benign. A proper evaluation by a veterinarian, including diagnostic tests and possibly a biopsy, is necessary for an accurate diagnosis.

A fatty tumor, also known as a lipoma, in cats typically appears as a soft, movable, and well-defined lump under the skin. Lipomas are benign tumors composed of fatty tissue and are one of the most common tumors found in cats. They can vary in size, ranging from small pea-sized nodules to larger masses. Lipomas are generally slow-growing and do not cause pain or discomfort unless they become large or impede movement. However, having any new or changing lumps examined by a veterinarian to confirm the diagnosis and rule out other more concerning conditions is important.

Iris melanosis, which refers to increased pigmentation of the iris (the colored part of the eye), is generally not painful in cats. It is a benign condition commonly seen in older cats, and the development of dark spots or patches on the iris characterizes it. Iris melanosis is typically harmless and does not require treatment unless it progresses to iris melanoma, a rare malignant tumor. Regular monitoring by a veterinarian is recommended to detect any changes in the iris pigmentation and ensure early intervention if necessary.

Iris melanoma is a rare malignant tumor arising from the pigment-producing cells (melanocytes) in the iris of a cat’s eye. It can present as pigmented nodules or masses on the iris surface and may cause eye appearance changes. Iris melanoma is a serious condition that can impair vision or spread (metastasis) to other body parts. Regular eye examinations by a veterinarian, particularly in cats with preexisting iris melanosis or other risk factors, are important to detect and monitor any changes in the iris and initiate appropriate treatment if necessary.

Skin cancer in cats can sometimes be accompanied by itchiness, but it is not always the case. Itching or discomfort can vary depending on the type and location of the skin cancer. For example, basal cell carcinomas or squamous cell carcinomas on the skin may cause itching or ulceration. However, other types of skin cancer, such as mast cell tumors or melanomas, may not necessarily be associated with itching. Suppose you notice changes in your cat’s skin, including lumps, sores, or unusual itching. In that case, it is important to have a veterinarian evaluate the area for an accurate diagnosis and appropriate treatment.

Yes, cats’ mammary tumors can be benign (noncancerous) or malignant (cancerous). Mammary tumors are relatively common in cats, especially in unspayed females. Spaying cats before their first heat significantly reduces the risk of developing mammary tumors. While some mammary tumors in cats are benign and may not pose significant health concerns, others can be malignant and potentially spread to other body parts. Early detection and surgical removal of mammary tumors offer the best chance for a positive outcome. Therefore, if you notice any new lumps or changes in the mammary area of your cat, it is important to have them evaluated by a veterinarian.

Melanomas in cats can vary in appearance depending on their location and stage. They may appear as darkly pigmented or black nodules, masses, or ulcers on the skin, mucous membranes, or other body areas. Melanomas can be solitary or multiple and may exhibit irregular borders or uneven pigmentation. However, the appearance of melanoma alone cannot definitively confirm its diagnosis, as other conditions, such as benign melanocytes, can have similar characteristics. A proper evaluation by a veterinarian, including diagnostic tests and possibly a biopsy, is necessary to determine if a suspected melanoma is indeed malignant.

In the early stages, melanoma in cats may appear as small, pigmented or darkly colored nodules, lesions, or spots on the skin or mucous membranes. These early-stage melanomas are often localized and have not spread to other body areas. Early detection and intervention offer the best chance for successful treatment. Regularly monitoring your cat’s skin, mucous membranes, and any existing pigmented areas, such as the mouth or ears, is important to detect any changes or suspicious lesions. If you notice any new or changing pigmented growths on your cat, it is advisable to have them examined by a veterinarian for proper evaluation and diagnosis.

The treatment and management of cat tumors depend on various factors, including the type, location, and tumor stage. Shrinkage of tumors in cats can be achieved through various treatment modalities, such as surgery, radiation therapy, chemotherapy, immunotherapy, or a combination of these approaches. The veterinarian will determine the specific treatment plan based on the individual cat’s condition and the characteristics of the tumor. It is crucial to consult a veterinarian who can assess the tumor and recommend the most appropriate treatment options for your cat’s situation.

Tumors in a cat’s mouth can have various causes, including benign and malignant conditions. Some common types of tumors in a cat’s mouth include squamous cell carcinoma, fibrosarcoma, melanoma, and oral tumors associated with feline odontoclastic resorptive lesions (FORLs). Certain risk factors, such as chronic inflammation, viral infections (e.g., feline leukemia virus or feline immunodeficiency virus), or exposure to certain carcinogens, may increase the likelihood of developing mouth tumors in cats. Regular dental examinations, oral health care, and routine veterinary check-ups can help detect abnormalities or tumors in the mouth early and facilitate prompt intervention.

The survival time for cats with skin cancer can vary depending on several factors, including the type, location, stage of cancer, and the effectiveness of treatment. Some skin cancers in cats, such as squamous cell carcinomas or mast cell tumors, can be successfully treated if detected early and appropriate treatment is initiated. Cats can live for several years or more with proper management in these cases. However, other types of skin cancer, such as aggressive melanomas or certain malignant sarcomas, may have a poorer prognosis, with survival times ranging from several months to a year or less. The best action is to consult a veterinarian who can assess the specific case and provide guidance based on the cat’s situation.

The progression of cancer in cats can vary depending on the type and stage of the cancer. Some cancers may grow slowly, while others can be more aggressive and spread (metastasize) to other body parts. The specific progression of cancer in cats depends on factors such as the tumor’s location, invasiveness, overall health, and the effectiveness of treatment. Regular veterinary check-ups, monitoring, timely intervention, and appropriate treatment can help manage cancer progression and improve the cat’s quality of life.

Diffuse iris melanoma in cats is diagnosed through a combination of methods. The veterinarian will perform a thorough eye examination, including visual inspection and evaluation of the iris. Diagnostic tests such as ultrasound, tonometry (measuring eye pressure), and ophthalmoscopy (examining the eye’s interior) may be conducted to assess the extent of the melanoma and determine if it has spread. Additionally, a tumor sample may be obtained through fine-needle aspiration or biopsy for further analysis by a veterinary pathologist. The pathologist’s evaluation of the tissue sample can confirm the diagnosis and provide information about the melanoma’s characteristics and potential aggressiveness.

The treatment approach for diffuse iris melanoma in cats depends on the individual case and the extent of the tumor. Treatment options may include surgical removal of the affected eye (enucleation), radiation therapy, cryotherapy (freezing the tumor), or a combination of these approaches. A veterinary ophthalmologist or oncologist will determine the specific treatment plan based on the cat’s overall health, the tumor’s characteristics, and the desired outcome. It is important to consult a specialist who can provide expert guidance and recommend the most appropriate treatment options for your cat’s situation.

Currently, there is no specific vaccine available for feline melanoma. Vaccines are crucial in preventing infectious diseases but are not typically used to prevent or treat cancer, including melanoma, in cats. Prevention strategies for melanoma in cats focus on reducing risk factors such as limiting sun exposure, providing shade or protective clothing, and avoiding known carcinogens. Regular veterinary check-ups, routine skin examinations, and early intervention are important for detecting and managing melanoma in cats.

The cost of treating melanoma in cats can vary depending on several factors, including the specific treatment plan, the stage and extent of the melanoma, and the geographical location. Treatment options for melanoma may include surgery, radiation therapy, chemotherapy, or a combination. Each treatment modality has associated costs, including diagnostic tests, medications, anesthesia, surgical procedures, and follow-up care. Treating melanoma can range from a few hundred to several thousand dollars. It is advisable to consult with a veterinarian or veterinary oncologist for a detailed estimate based on the specific case and 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.

Similar Posts