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Skin Cancer in Cats: Causes, Signs & Care (Vet Answer)

Dr. Joe Mallat

By Dr. Joe Mallat

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Dr. Joe Mallat

DVM (Veterinarian)

The information is current and up-to-date in accordance with the latest veterinarian research.

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Cats can develop skin cancers just like people. As a cat owner, noticing a lump on your cat can cause great concern and uncertainty. What is it? Why is it there? And is my cat going to be okay? Diagnosis and treatment of feline skin cancers have progressed significantly over the past few decades.

In this article, discover answers to common questions, as well as guidance about what to do to ensure the best outcome for your cat.

What Is Skin Cancer in Cats?

Skin cancers are growths or lumps on the skin. These can occur due to normal cells multiplying in an abnormal fashion, or abnormal cells proliferating in abundance. Skin cancers can occur on many parts of the body—the face and head, the legs and belly, and even the trunk and tail. There are too many different skin cancers in cats to cover in this article, though we will dive into the most common ones below.

Technically, a skin cancer is a skin tumor that is malignant, whereas a benign skin tumor is a tumor that behaves less aggressively. Benign tumors grow less rapidly, do not spread to other organs, and are relatively easy to remove. Cancerous tumors, on the other hand, grow quickly, spread throughout the body, and can be difficult to treat. To avoid confusion, this article will use the term skin cancer to refer to any lump on the skin of the cat, and we will differentiate benign from malignant skin cancers where appropriate.

What Are the Most Common Skin Cancers in Cats?

Common benign skin cancers in cats:
  • Lipomas (fatty deposits)
  • Cysts
  • Adenomas
  • Basal cell tumors

While these tumors are benign, they can grow to a large size and cause discomfort for your cat.

Common malignant skin cancers in cats:
  • Squamous cell carcinomas
  • Soft tissue sarcomas
  • Mast cell tumors
  • Cutaneous lymphoma

Some other cancers, such as mammary cancer, can spread or metastasize to produce lesions on the skin.

What Are the Signs of Skin Cancer in Cats?

The most common sign of skin cancer in cats is a visible lump or a lump that can be felt on or under the skin. In the early stages, however, this can be difficult to detect, as the relatively long coat of cats can mask the lump. Other cancers that occur on the hairless parts of the body, such as squamous cell carcinomas of the nose and ears, are more readily identified early on. Skin cancers can occur in isolation (a solitary tumor) or multiples.

Cats licking or over-grooming a particular area can be another sign that skin cancer is present. Cats do this because the skin cancer feels uncomfortable (remember, it isn’t meant to be there), or because the lump has become ulcerated and infected. If the skin cancer is linked to a viral disease or has spread through the body, some cats will show general signs of illness and malaise, though this is rare.

ginger cat check by vet
Image Credit: Nestor Rizhniak, Shutterstock

What Are the Causes of Skin Cancer in Cats?

In broad terms, skin cancers are caused by abnormal and uninhibited growth of cells. Most cells in the body exist in a tightly regulated cell cycle, in which they die and reproduce to maintain normal body functions. With skin cancers, this regulation process is shut off, leading to “overgrowth” of cells. Malignant skin cancers often have abnormal, large, and infiltrative cells, whereas benign skin tumors are more likely to resemble proliferations of normal cells.

While most skin cancers occur due to errors in the cell cycle, the actual cause is rarely identified. Instead, numerous factors may be at play, including genetic, environmental, and viral factors. Some cats with viral diseases such as Feline Leukemia Virus (FeLV) and Feline Immunodeficiency Virus (FIV), are more likely to develop certain skin cancers. White-coated cats that sunbake or spend time outdoors are more likely to develop sun-damaged skin on minimally-haired parts of the body, such as the nose and ears. This solar irritation is considered a precursor to squamous cell carcinoma formation. Other skin cancers occur without an identified cause.

How Do I Care for a Cat with Skin Cancer?

Caring for a cat with skin cancer should always start with a visit to the veterinarian. Feeling a lump on your cat does not automatically mean that your cat has skin cancer. The appearance of a lump alone does not tell us anything about how serious the lump is. Indeed, it may be something benign, such as a lipoma or cyst, or it may not be a cancer at all (some abscesses or swellings can feel like lumps).

Your vet will discuss the appropriate next steps. Some benign skin cancers can be left alone and closely monitored, if they are small and not causing any issues. Other malignant skin cancers require more aggressive intervention, such as surgical removal or radiation therapy. Unfortunately, most viral diseases causing skin cancers in cats are very difficult to treat.

Regularly feeling your cat to check for lumps is important. Any suspicious or abnormal skin lesion warrants a prompt visit to your local vet, who can decide if further testing is necessary. As with many cat diseases, early intervention leads to the best health outcome.

cat lying being massaged by owner
Image Credit: Pencil case, Shutterstock

Frequently Asked Questions

How Are Skin Cancers in Cats Diagnosed?

Skin cancers in cats are diagnosed using a number of tests. Blood tests may be performed to check for infection with FIV or FeLV. In-house tests such as skin scrapes or fine needle aspirates can be performed to examine cells under the microscope. Generally, for a conclusive diagnosis, a general anesthetic and surgical biopsy are required. The cancerous tissue is then sent to the laboratory to be analyzed by a specialist veterinary pathologist.

How Do I Prevent Solar-Induced Skin Cancers?

If you have a white cat with pale (non-pigmented skin), particularly around the face, it may be prudent to keep them indoors to avoid sunburn and reduce the risk of squamous cell carcinomas. If your cat does venture outside, always apply a cat-safe sunscreen, especially throughout the day.

White cat indoor staring at the window
Image Credit: Taya Ovod, Shutterstock

What Is the Prognosis for a Cat with Skin Cancer?

The prognosis for cats with skin cancer is highly variable. This will depend on what the cancer is, where it is located on the body, treatment options available, and the presence of underlying viral diseases. For example, basal cell tumors and cysts can be fairly easily cured with surgical removal, but soft tissue sarcomas and cutaneous lymphoma carry a much poorer prognosis.


Skin cancers are relatively common in cats, especially as they reach older age. While some skin cancers are certainly cause for concern, others are more benign. Regularly checking your cat’s skin for lumps is always a good idea. Additionally, seeking veterinary guidance as soon as you notice a lump will lead to a more favorable outcome for both you and your cat.

Featured Image Credit: brodtcast, Shutterstock

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