While skin cancer is often related to sun exposure, and thus occurs in areas with less fur, there are some kinds that are not related to sun exposure at all. Happily, cats are less likely than other animals to get skin cancer that is not UV triggered, such as mast cell tumors.

Indeed, if the cat has one black ear and one white, the white ear is much more likely to be affected by SCC.

Some aggressive tumors are great mimics, and take on the characteristics of innocent lumps, such as being superficial or slow growing. However, at some point in the future, they may become aggressive. It is difficult to distinguish a harmless skin lump from a sinister one, just by looking at it with the naked eye. [7] X Expert Source Jamie Freyer, DVMLicensed Veterinarian Expert Interview. 8 October 2021. The only way to tell for sure whether or not a lump is harmful is to have the lump removed and a biopsy of it sent to the lab. [8] X Research source

When you first find a lump, measure it with a ruler and record the measurement. Repeat the measuring process every week so that you can establish if the lump is changing or not.

In the early stages of squamous cell carcinoma, non-pigmented skin becomes inflamed and looks darker pink than the surrounding skin. The skin will take on a scaly appearance and it can be mistaken for ringworm. Ulceration means that the lump breaks open and becomes a wound. If you notice this, seek medical help for your cat.

The lump instead infiltrates deeply into the skin, so that the skin appears “glued” down to the tissue beneath.

If the cancer affects an ear, the edge of the ear may become irregular in shape, almost as if small bites have been taken out of it.

If possible, get a sunscreen that is made specifically for cats. If there is none available in your area, use a sunscreen designed for children and choose the highest SPF available. Always check the ingredients and avoid using a lotion that contains octyl salicylate and zinc. These are not good for cats, as they may swallow the product and be exposed to potentially toxic effects while grooming.

Call your veterinary office and tell them what you have found. Make an appointment to have your cat seen as soon as possible, so that if there is a problem, you can begin treatment right away.

This is a non-invasive procedure that is done with the cat fully conscious and most cats tolerate the process well.

A histology test determines if the lump is cancerous.