Cats and Skin Cancer

They're covered with fur, so cats can't get skin cancer, right?  Wrong!  They can get skin cancer - and that includes indoor cats, too.  The chief cause is exposure to the sun, just like humans.  Because cats love warmth, outdoor cats tend to find sunny spots to sleep in during all seasons and the same is true for indoor cats.  They may camp out in window hammock or on a couch or even the floor where there's a sunny spot.  Cats with light colored or thin fur and those with no hair are at a greater risk for cancer. 

Genetics, a trauma or injury that leaves a scar, and chronic skin allergies that causes cats to scratch or lick an area can also cause cancer.  Other than genetics, these possible causes involve a mark or scar on skin that can cause irritation.

While there are lots of types of feline skin cancer, there are four that are the most common.  According to petmd.com, they are:

• Basal cell tumors - usually found on the head, neck and shoulders but can be other places.  These are usually benign and surgery will remove them.
• Mast cell tumors - Mostly found on the head but can also be on the neck and legs. These occur most often in middle-aged cats and, in particular, Siamese cats.
• Squamous cell carcinoma - spreads rapidly and more common in cats with light colored skin and usually on the face, nose and ears of white-faced cats.  Because this form of cancer itches, cats often scratch leaving scabs.
• Fibrosarcoma - these are tumors found in connective tissue anywhere in the body but sometimes where cats have had injections, fluids or vaccines (neck and near the back legs).  Because of their location, these tumors can grow quickly and be hard to remove.

Tumors like those above can be hard to identify.  They might not always be noticeable just by looking at your cat.  Purina.co.uk lists these signs:
    •    Scabbing, particularly on the ears, nose or eyelids.
    •    Black, crusty patches of skin.
    •    Weeping, raw skin.
    •    Red and raised areas of skin.
    •    Wounds that won’t heal.
    •    Ulcers.
    •    General lethargy.

By petting your cat and massaging as you go, you might find unusual bumps or lumps.  If you are concerned about anything unusual about your cat's skin or that you feel under the fur, contact your vet right away.  Cancers can grow and spread quickly so waiting to contact your vet might be fatal to your cat.

To determine if a cat has skin cancer, vets will to a cytology test, where cells from the suspicious area get collected and examined.  It can be done fairly easily with surface skin cancers but a needle extraction might be called for if there are unusual lumps in your cat's skin.  In some cases, a look at cells under a microscope can make the diagnosis.  However, a tissue biopsy that can be sent to a lab and reviewed by a pathologist may also be necessary.   Depending on the results of the initial exam and tests, the vet may also ask for x-rays or additional cytology tests.

If your cat does have a form of skin cancer, how will your vet treat it?  That will depend on the type of cancer diagnosed, how severe it is and where the tumor is located.  Some cancers can be treated with topical medication, however, surgery is most frequently used to remove a cancerous tumor, which can help keep it from coming back.  If cancer has spread or the tumor can't be removed, chemotherapy or radiation might also be used.

The key thing to think about if your cat is often in the sun is prevention.  Unless your cat is genetically prone to developing skin cancer, keeping your cat from getting it is easy - just apply sunscreen to pink patches of skin or ears.  We do this for Stitch since he is a true sun worshipper!  Make sure that you only use a pet-friendly sunscreen that is ok'd by your vet.  Our blog about summer dangers for cats has some tips for choosing sunscreens.

CLICK HERE to read more from petmd.com

CLICK HERE to read more from  the New England Veterinary Care & Cancer Center.