You've heard all the warnings about using sunblock and not spending too much time in the sun to avoid skin cancer. If your cat goes outside, or spends most of his time in a very sunny place, he's also at risk. Ears are the most vulnerable areas.
Squamous Cell Carcinoma
Squamous cells are the outside layer of the epithelium, which lines all of the organs in your cat's body. The most common cause of squamous cell carcinoma in cats is overexposure to sunlight, or solar-induced carcinoma. According to Kansas State University College of Veterinary Medicine, skin cancer is the second most common type of cancer in felines. If you notice any changes in your cat's ears, take him to the vet as soon as possible.
Cats with light coloring on their heads and ears are at greater risk of squamous cell or solar-induced carcinoma than their darker-headed feline friends. Because the ears have such little hair covering, that's the area most at risk from skin cancer due to sun exposure. If your cat has a white face or ears, don't let him outside on hot, sunny days. If he loves sitting in a very sunny window, close the blinds or otherwise deny him access to the sill during the heat of the day.
The earliest sign of skin cancer on Fluffy's ear is a red area at the tip. He might lose hair on his ears, and skin on the ear tip may become flaky. His ears will eventually become crusty and scabby. Since many cats with squamous cell carcinoma develop numerous lesions, you might notice similar scabbing on his nose, eyelids, lips and temples. He might scratch at these sores. If not caught early and treated, these lesions start ulcerating, ooze fluids and appear tumor-like. While these tumors metastasize slowly, they can eventually spread into his lymph nodes and to the rest of his body.
After performing a skin biopsy and confirming that the lesions are skin cancer, your vet will likely surgically remove as much as of your cat's ear or ears as necessary to get rid of the malignancy. The Merck Veterinary Manual recommends margins of at least 2 centimeters around cancerous areas. Although Fluffy might look funny, he should recover well. Your vet might recommend putting sunscreen on your cat's ears during warm weather. If the cancer has spread, she might recommend treating your cat with radiation or chemotherapy.
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