Skin Cancer in Cats

Some cats are indoor cats. Others like to roam outdoors and return home at their leisure. It might seem odd or come as a surprise, but skin cancer can strike in either case. While exposure to the sun can increase the likelihood that a cat will develop skin cancer, some types are caused by other factors, such as genetics or the environment.

SRS for pets with Cancer cat

Because your cat’s fur can hide small bumps or discolored skin, you might have to proactively look and feel for problem areas on his or her skin. That holds even more true if your cat has fluffy fur. Any breed of cat and either sex can develop one or more of the many types of skin tumors that cats can get. Cats may have one isolated tumor, a couple of lumps or several. Fortunately, if a tumor is indeed cancerous, there are a range of treatment options that can help. Treatment can even be curative, depending on the type of cancer and how aggressive the cancer is when it is detected.

Types of Skin Tumors in Cats

There are several different types of skin tumors that cats can develop, but two classifications matter more than anything else: they are either benign (noncancerous) or malignant (cancerous).

Common benign tumors/skin issues:

  • Lipomas (fatty tumors)
  • Cysts
  • Adenomas
  • Basal cell tumors (the most common type found in cats)
  • Squamous cell carcinoma in situ
  • Plasmacytomas (some)
  • Melanoma tumors (can also be malignant)

Benign tumors are relatively harmless compared with cancerous ones, but larger tumors or those in locations that might impede a cat’s ability to function might still have to be removed. For instance, a large fatty lipoma on a cat’s hind leg or in its underarm area could prevent him or her from walking normally. Cat parents sometimes have benign lumps removed for cosmetic reasons, too. It’s important to note that determining whether a lump is benign should not be left to guesswork — only through pathology can a determination be made with certainty.

Malignant tumors:

  • Mast cell tumors
  • Soft tissue sarcomas
  • Squamous cell carcinoma (can appear around the eyes, nose and lips as well)
  • Hemangiosarcomas
  • Plasmacytomas
  • Cutaneous lymphomas
  • Histiocytic tumors

Other types of cancer can also metastasize (spread) to a cat’s skin. These include mammary cancer and bladder cancer.

Signs of Skin Cancer in Cats

The most obvious symptom of skin cancer in cats would be a visible tumor or a palpable mass. Spotting one might be easier said than done, however. Until a tumor begins to grow, it likely would be hidden by your cat’s fur. Some types of cancers reveal themselves through behavioral changes, but a cat with skin cancer might not act any differently unless a malignant tumor causes discomfort, a benign lesion becomes infected or if the cancer is advanced enough to have spread. Since these symptoms of skin cancer in cats are not readily visible, you can proactively look and feel for skin issues periodically by petting your cat. You can also double-check that your veterinarian does so during regular wellness visits. Another potential sign of a skin issue is incessant licking of an area beyond the amount of licking that would be normal for grooming. A growth could be irritating your cat, or incessant licking due to an allergy or stress could cause a lick granuloma, which is a red, raised lesion rather than a tumor. More likely, though, a cat might lick a mass on its body because it is something out of the ordinary. It’s not supposed to be there, so they lick at it.

Workup & Diagnosis

If you discover a lump under your cat’s skin, your veterinarian can perform an examination and some procedures to determine what it is and whether it is cancerous or not. In addition to a visual exam, you can expect the vet to perform a fine needle aspiration to withdraw a small sample of cells or tissue from the mass. This sample typically is sent out to a pathologist, who views the cells under a microscope to determine whether it is benign or malignant. The pathologist may also be able to determine the type of cancer, a biopsy may be needed to determine the nature of the mass. If a biopsy is ordered, you can expect your cat to subjected to bloodwork, urinalysis and chest X-rays to make sure he or she is healthy enough to undergo anesthesia. A complete workup will similarly be ordered if your veterinarian suspects the tumor is malignant. In this case, X-rays can help determine whether cancer has spread to the lungs. Some cancers spread to the regional lymph nodes. If a lymph node in enlarged in the region of the mass, your veterinarian will likely recommend taking a sample (aspirate, biopsy) as well. A biopsy will show the aggressiveness (or lack of aggressiveness) of a particular mass. The battery of tests, or work-up, will reveal the tumor’s stage of disease.

Treatment & Prognosis

There are a range of treatment options available for cats with skin cancer, while benign tumors may not require any further treatment.

Benign tumors: If pathology results show that a tumor is benign, additional treatment may not be needed. Sometimes a mass will be excised. If the growth was not removed, however, the veterinarian may measure it and document the size. That way, any additional growth can be noted during subsequent visits and treatment can be suggested as needed at that time. An example would be if a fatty tumor continues to grow and becomes bothersome due to size or location. A cat parent might also opt to treat a benign growth such as a sebaceous cyst. These raised, red growths on the skin can rupture or ooze, so removal is an option. Alternatively, a course of antibiotics may be recommended.

Malignant tumors: The preferred go-to treatment for a malignant tumor often is surgical removal when possible. Achieving “clean” margins is the goal when excising the mass. This means that the tissue around the outer edges of the removed portion shows no cancer. This type of surgery can be curative for certain malignant masses. Sometimes surgery may be accompanied by radiation therapy. Radiation may also be the primary treatment if for some reason surgery is not or cannot be performed.

There are two primary types of radiation therapy. Traditional radiation, known as conventionally fractionated radiation therapy (CFRT), typically requires 15 to 21 treatment sessions. A newer, more innovative approach called Stereotactic Radiation uses a higher radiation dose and ultra-precise targeting that focuses even more on the tumor. Because of the higher dosage, only one to three sessions are needed — and thus a cat only has to be anesthetized one to three times instead of 15 to 21. The precision targeting also is designed to limit damage to adjacent healthy tissue. Stereotactic Radiation treatments are a specialty at PetCure Oncology.

An even more comprehensive treatment approach might be indicated if the type of skin cancer is very aggressive or if it appears the cancer has spread, for example, into the lymphatic or vascular system or to other areas on the skin. Chemotherapy, administered under the guidance of a veterinary medical oncologist, might become part of the treatment mix under such circumstances.

Some types of feline skin cancer will come back at some point even with treatment. However, a cat can do very well and have a good quality of life for several months to years. However, very aggressive cancers might spread in a period of a few months. If that’s the case, closely monitoring your cat’s quality of life will be important until the next decision has to be made.

Find a PetCure Oncology Location Near You

At PetCure Oncology, we proudly go beyond offering treatment for skin cancer in cats. We also offer a level of compassionate and support that reflect our understanding of your love for your cat. Our innovative treatment options are proof of our mission to extend your time with your cat while giving him or her the best quality of life possible. For more information about PetCure Oncology and our treatment options, find a location near you today.


  1. National Cancer Institute Center for Cancer Research. Accessed July 25, 2018, from https://ccr.cancer.gov/Comparative-Oncology-Program/pet-owners/disease-info
  2. Morris Animal Foundation. Accessed July 25, 2018, from https://www.morrisanimalfoundation.org/article/your-cats-best-defense-against-cancer-may-be-snuggling-you
  3. Morris Animal Foundation. Accessed July 25, 2018, from https://www.morrisanimalfoundation.org/sites/default/files/files/2018-03/00000-MBS_UTF_CancerChecklist_F1.pdf
  4. Accessed July 25, 2018, from https://www.petmd.com/blogs/thedailyvet/drjintile/2014/december/finding-causes-cancer-cats-and-dogs-32278
  5. Diamondback Drugs. Accessed July 25, 2018, from https://www.diamondbackdrugs.com/what-kinds-of-cancers-are-most-common-in-cats/
  6. Pet Health Network. Accessed July 25, 2018, from https://www.pethealthnetwork.com/cat-health/cat-diseases-conditions-a-z/cancer-and-cats-what-every-pet-parent-should-know
  7. American College of Veterinary Surgeons. Accessed August 8, 2018, from https://www.acvs.org/small-animal/bone-tumors
  8. Veterinary Society of Surgical Oncology. Accessed August 8, 2018, from https://www.vsso.org/index.php/education-new/cancer-information-new/cancer-in-cats-by-tumor-type-new/9-education-1/education/309-brain-tumors-feline
Types of Cancers In Cats

If your pet is displaying any symptoms of cancer or has been diagnosed with cancer, sort below by cancer type or tumor location to learn more about each cancer type and available treatment options for your pet. Click on the links for more specific information on treatment and real patient stories.




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