Skin Cancer in Cats

Causes, Treatment, and Prevention

Maine coon cat lying on grey carpet.
Cats of all breeds can unfortunately develop skin cancer.

Getty Images/Elena Svecova / EyeEm

Skin cancer in cats is treatable but can be fatal if unaddressed. Out-of-control cell growth, often caused by excessive exposure to sunlight, can lead to cancerous tumors on the skin. Some cats are genetically predisposed to skin cancer, and some breeds are more susceptible. Cats with light or minimal fur, especially Siamese cats, are at higher risk of skin cancer. Your vet will diagnose skin cancer with a comprehensive physical exam and various tests. Treatment usually involves surgical removal of the cancer and sometimes chemotherapy or radiation therapy. The prognosis is good for cats who receive surgery early in cancer development. Preventative measures include close monitoring of your cat's skin and minimizing its exposure to sunlight.

What Is Skin Cancer?

Skin cancer is the uncontrollable growth of mutated cells in the epidermis caused by unrepaired DNA damage. The cell growth usually manifests as malignant tumors on the skin that worsen over time. Different skin cancers in cats include malignant melanoma, fibrosarcoma, mast cell tumors, and squamous cell carcinoma. Squamous cell carcinoma is the most common.

Symptoms of Skin Cancer in Cats

Skin cancer in cats isn't always apparent. Monitor your cat's skin and take seriously any worrisome symptoms your cat may display.


  • Lump or bump on or under the skin
  • Marks or growths on the skin
  • Hair loss
  • Discoloration of the skin or fur
  • Skin inflammation or rash
  • Sores or ulcers that won't heal
  • Bruising
  • Itching

Initially, symptoms of skin cancer in cats may be difficult to notice. The clearest sign of skin cancer in a cat is a lump or bump on your cat's skin. Other symptoms include sores or oozing ulcers, rash, and itchy skin. Still, not all tumors are cancerous, and only your vet will be able to diagnose the cancer. The best way to observe symptoms in your cat is to pay attention to irregularities while brushing or petting. If you notice something unusual, visit your vet right away.

Causes of Skin Cancer

There is not always a known cause for a cat's skin cancer, but several factors may play a role in developing the disease.

  • Sun exposure: The leading cause of skin cancer in cats is prolonged exposure to the sun. Cats that spend a lot of time outdoors or under bright light on a windowsill are at risk of getting a sunburn that could develop into skin cancer. Cats with lighter, shorter fur are more prone to sunburns.
  • Hereditary predisposition: Based on their family history, some cats are predisposed to skin cancer. Malignant melanoma is genetic, while other forms of skin cancer are not.
  • Skin trauma: Some cases of skin cancer in cats are thought to be caused by trauma to the skin, including excessive licking or severe injury to the skin.

Diagnosing Skin Cancer in Cats

Your vet will perform a complete physical examination to diagnose your cat with skin cancer. Various diagnostic tests may be performed, including biopsies, cytology, blood tests, and fine-needle aspirates. Sometimes, an x-ray or ultrasound is necessary to see if the cancer has spread. If your cat has benign marks or growths, your vet will monitor them as it ages to ensure that it doesn't become cancerous.


The treatment for skin cancer in cats will vary depending on its type and severity. Surgery is usually the best treatment for skin cancer. Surgery is straightforward and effective when caught early while the tumor is relatively small. If the cancer has spread or the tumor is too large for removal, your vet may suggest chemotherapy or radiation therapy. Some cats may not qualify for chemotherapy or radiation therapy due to preexisting health conditions or age.

Prognosis for Cats With Skin Cancer

Like the treatment methods for cats with skin cancer, the prognosis depends on many factors. If your cat's cancerous growth has been successfully surgically removed or the chemotherapy has been effective, the prognosis is good, and recovery will be swift. However, if your cat's skin cancer has spread to other organs, the prognosis isn't as optimistic. Even with treatment, skin cancer can return, so if your cat has a history of cancer, monitor it closely for any new marks or growths.

How to Prevent Skin Cancer

Skin cancer in cats cannot be prevented entirely, but there are several measures you can take to lower its likelihood of developing. The use of nonadjuvanted vaccines is recommended to limit the chance of your cat developing an injection-site sarcoma. If you have a hairless cat, use pet-friendly sunscreen. You should not breed cats with a history of skin cancer if there is a genetic component to the disease, and you should keep white or hairless cats out of direct sunlight.

  • Is skin cancer in cats treatble?

    Surgical removal of a cat's skin cancer is highly effective. It's essential to pay attention to any abnormalities on your cat's skin, as the earlier the surgery is performed, the better.

  • My cat likes to sunbathe, is that okay?

    Some sunbathing is okay for cats, but you should minimize your cat's exposure to direct sunlight and encourage laying in the shade. If you have a Siamese cat, this is especially important.

  • How will my vet know if my cat has skin cancer?

    The surest way to diagnose skin cancer in a cat is with a biopsy or fine-needle aspiration. If you notice symptoms of skin cancer at home, visit your vet for a definitive diagnosis.

If you suspect your pet is sick, call your vet immediately. For health-related questions, always consult your veterinarian, as they have examined your pet, know the pet's health history, and can make the best recommendations for your pet.