Cats and skin cancer; what is it, how do we recognise it, and what can we do about it?

Cats and skin cancer; what is it, how do we recognise it, and what can we do about it?
August 1, 2018 kernow

Many owners are shocked to hear that their cat has skin cancer, as they didn’t know cats could get skin cancer in the first place! Sadly, this is the reality for many of our feline friends. You may have three big concerns; what exactly is skin cancer in cats, how can we recognise it, and what can we do about it? Let us discuss the ‘big three’ in cats…

  1. Mast Cell Tumours

What are they?

In the body, mast cells are a type of white blood cell that plays an important role in defending the body from infection, as well as helping heal wounds. For allergy sufferers, mast cells bring the dreaded histamine; histamine is released causing itchiness (and anaphylaxis in severe allergy). Mast cells contain granules of histamine and heparin; despite getting a bad reputation for causing itchiness, they are there to protect your body. However, when they multiply uncontrollably, they cause mast cell tumours (MCTs). MCTs are the most common form of skin tumour in dogs, but also make an unwanted appearance in cats. They vary in their malignancy (aggressiveness), but are generally bad news.

How can we recognise them?

MCTs vary enormously in size, but they can be found in the skin, and older cats are particularly susceptible (interestingly, those with allergies are not at a heightened risk). Some signs to look out for characteristically include:

  • Itchiness
  • A red swelling
  • A palpable mass
  • Change in hair direction

“And for my next trick, I will disappear…”

BEWARE – MCTs can swell up and reoccur. Don’t be lulled into a false sense of security because the mysterious swelling has disappeared, that is the MCT’s party trick!

It is a great idea to perform regular, full-body, nose-to-tail exams on your cat. It can be during evening petting as Felix is curled up on your knee, or while Sylvester is standing quietly and willing to be touched all over. For all he knows, you just want to show your affection!

What can we do about them?

Typically, these tumours can be removed in an operation, hoorah! However, the more they have spread, the worse the prognosis.

 Squamous Cell Carcinomas

What are they?

Picture this – a serene white cat, stretched out on a beautifully preened lawn in the sunshine. Bliss, no? No. The sun is a big risk for white cats: squamous cell carcinomas can be triggered by sun exposure. Squamous cells make up the uppermost layer of skin; like all cancers, squamous cell carcinomas (SCCs) occur when a generally useful cell population expands out of control. These tumours are malignant (cause disease in cats), invasive, and can metastasise (spread to new organs other than the skin). Typically, older and white cats are at higher risk.

How can we recognise them?

  • Ulcers: not just any skin ulcer, but crusty, bleeding ones which will not heal
  • Different skin colouration
  • Hair loss
  • Keep an eye on the front of the nose, ear tips, lips and eyelids, as they may be particularly susceptible (however, SCCs can be found anywhere).

What can we do?

These tumours are fast growing and invasive; in other words, the faster we act, the better the prognosis. Biopsies will be taken of lumps to perform “cytology” (cell analysis) to determine what type of cancer, if any, a suspected lump is. If SCC is suspected, X-Rays may be necessary to see if the SCC has moved to any other sites.

There are different treatment avenues, depending on the severity and number. Small, isolated tumours may be removed by cryosurgery (a special type of freezing), and larger ones may require surgical operations for removal. If the whole tumour cannot be eradicated, chemotherapy may be suggested.

  1. Basal Cell Carcinomas

What are they?

In dogs, MCTs are the most common skin cancer; in cats, it’s Basal Cell Tumours (BCTs), forming up to a quarter of all skin tumours. The skin has many layers; the deepest of these is made up of the basal epithelium. When these mutate, basal cell tumours can develop. Older cats, as in most cancers, are most at risk; along with this, Siamese cats are commonly affected.

 How can we recognise them?

These tumours are usually benign, meaning they cause few health issues in most cats. As such, they tend to be well-contained, or “well-circumscribed”, solitary masses; they will be raised, hairless, and found most often around the head, neck and shoulders. These can grow very large, and become damaged (ulcerated).

What can we do about them?

To diagnose them, we will take a sample of cells to analyse under a microscope, looking for abnormal cells. This procedure is done by a “fine needle aspirate”; a small needle will be inserted into the mass, and the cells prepared on a slide to be analysed under a microscope. Ideally, we will perform a full health analysis including a blood profile, too. Fortunately, as they tend to form one discrete mass, they can generally be surgically removed. Most cats recover well after surgery.

Take home messages

  • Three common types of skin cancer in cats are:
    • Mast Cell Tumours – itchy!
    • Squamous Cell Tumours – most likely to be malignant!
    • Basal Cell Tumours – most common!
  • It is great practice to perform a full body examination of your cat (watch out for the sensitive belly!)
  • Stay alert for:
    • Malaise in your cat;
    • Skin ulcers;
    • Patches of baldness or changes in hair direction;
    • Areas of redness in the skin;
    • Lumps, bumps, and areas of raised skin;
    • Wounds and infections.
  • Be careful about white cats in the sunshine.
  • Contact us as soon as possible if you have concerns of changes in your cat’s skin; the sooner we are aware of an issue, the sooner we can work to fix it!

We wish you and your furry friends a healthy and happy summer!

“Owners of dogs will have noticed that, if you provide them with food and water and shelter and affection, they will think you are god. Whereas owners of cats are compelled to realize that, if you provide them with food and water and shelter and affection, they draw the conclusion that they are gods.” 
― Christopher Hitchens