Before you go outside in the sun, you probably put on sunscreen or wear protective clothing to reduce your risk of developing skin cancer. But have you ever thought about providing the same preventative care to your cats?

Many pet parents are surprised to learn that some of the most common forms of cat cancer occur on the skin. One type of skin cancer, in particular—squamous cell carcinoma—is believed to be a result of overexposure to the sun’s ultraviolet rays. What’s worse is that these tumors are often visible but may not be recognized until it’s too late.

In order to reduce your cat’s risk of developing cancer, here’s what you should know.

Squamous cell carcinoma and its risk factors

Squamous cells are scale-like cells that lay flat on the outermost layer of your cat’s skin. They make up the “epithelium”—a layer of tissue that lines both the internal and external surfaces of the organs. If changes to these cells’ DNA occur, the cells can begin to multiply uncontrollably, resulting in a tumor.

Squamous cell carcinoma (SCC) is a form of cancer that affects these cells, causing tumors and/or sores on the skin. It’s one of the most common forms of skin cancer discovered in cats. Fortunately, SCC typically has a good prognosis if it is discovered early. Tumors can generally be removed if they’re in their early stages. However, if cancerous growths are undetected or untreated, the tumor can metastasize and potentially become fatal.

SCC can also present in another form—oral SCC—which affects the tissues inside the mouth. Oral SCC is much more dangerous than cutaneous (skin) SCC.

SCC of the skin most commonly affects cats whose fur or skin pigmentation do not adequately protect their skin from harmful UV rays. Cats with white or light-colored fur, thin fur or no fur tend to develop SCC tumors more frequently, especially if they spend lots of time exposed to the sun. However, any cat can develop skin cancer.

Most cases of SCC affect areas around the face, including the ears, nose, temples and eyelids. Less commonly, tumors can develop in other parts of the body, such as the toes and nail beds. Although most cats will develop only one tumor or lesion, some can develop multiple tumors at a time in the same region.

Spotting the early signs of skin cancer in cats

Cat owners should be vigilant about checking for signs of skin cancer in their cats to ensure early diagnosis and treatment.

SCC can take on numerous forms, which can make it slightly more difficult to identify on sight. In general, you should be mindful of any strange or new lumps, bumps or sores on your cat’s skin, especially if they appear to grow over time.

SCC may cause a small lump that has an irregular border or is oddly shaped. This bump may be different colors, ranging from white to pink or red and sometimes dark brown or black. The skin surrounding the tumor might appear pink, and the hair around the area might be sparse or completely lost.

In other cases, the cancer might produce shallow or deep lesions or sores that do not heal. Initially, these sores may appear similar to a scab or a scratch. Over time, the surrounding area might begin to swell, and the lesion will begin to grow larger. The sores may even produce discharge or bleed.

Can skin cancer be treated?

SCC is one form of cat cancer that can be treated effectively, but only if it is caught early. Small tumors may be able to be surgically removed, often resulting in a good prognosis for the cat’s health. Larger tumors may need to be treated through radiation therapy, cryotherapy (which freezes the tumor) or chemotherapy injections.

Unfortunately, if the tumor has begun to spread internally, treatment becomes much more difficult. These tumors are not as easily removed, and your cat may require chemotherapy or radiation therapy to control the cancer’s spread.

Squamous cell carcinoma may be preventable

An even more comforting note about SCC is that it may be preventable. Cat owners should be mindful of how often their cats are exposed to UV rays and take steps to minimize their exposure to reduce their risk for skin cancer. Try installing sunshades or UV blocking screens to protect cats indoors or apply a cat-safe sunscreen to your pet—particularly around their face.

Even if preventative measures are not effective, there are numerous ways to detect the presence of an SCC tumor before it grows too large to control. Conducting at-home examinations once a week can help you spot early signs of lesions or abnormal growths and get your cat to the vet right away. Your cat should also be seen for a professional exam annually, where your vet will check for signs of cancer.

By remaining vigilant about checking your cat for signs of skin cancer, you can get them the treatment they need and prolong their health and happiness.