Skin Cancer in Cats: Signs, Treatment, and Outlook
By Dr. Zubair Khalid, DVM, MS, PhD ·
Skin cancer in cats is a group of tumors that start in the skin or the tissue just beneath it, and it is the most common type of tumor vets find in cats [1]. Some are benign lumps that are easy to remove, while others are malignant and need prompt treatment. The location matters a great deal, because tumors on the ears, nose, and eyelids behave differently from lumps on the body.
This article is educational and is not a substitute for veterinary diagnosis or treatment.
Quick Answer
- Any new lump, crusty sore, or non-healing scab on your cat's ear, nose, or eyelid deserves a veterinary exam, because these sun-exposed areas are common sites for malignant skin tumors.
- Benign tumors such as basal cell tumors are common in older cats and are usually cured with surgery [1].
- Malignant tumors like squamous cell carcinoma (SCC) can spread locally and destroy tissue, so early detection gives your cat the best chance.
- Diagnosis almost always requires a sample of the tissue, not just a look with the naked eye.
- Treatment may include surgery, electrochemotherapy, photodynamic therapy, or topical medication, depending on the tumor type, size, and stage [2][3][4].
What Cat Skin Cancer Actually Is
The skin is the largest organ in a cat's body and can make up as much as one quarter of its body weight [5]. It has several layers, including the epidermis on top, the dermis underneath, and the subcutis at the deepest level, plus appendages like claws and sebaceous glands [5]. Tumors are abnormal growths of cells, and they can arise from any of these layers [1].
Vets divide skin tumors into benign and malignant. Benign tumors grow in place and do not spread to other organs. Malignant tumors, which is what we mean by cancer, can invade nearby tissue and sometimes spread through the body.
The most common skin tumor in cats is basal cell tumor, which is benign despite sometimes looking alarming [1]. The most common malignant skin tumor in sun-exposed areas is squamous cell carcinoma. Other skin cancers exist, including mast cell tumors and fibrosarcomas, but SCC and basal cell tumors account for many of the lumps owners notice on the head.
Signs of Skin Cancer in Cats
Owners usually spot skin cancer by seeing or feeling something new. The challenge is that many skin problems look similar, from allergies to infections to tumors. If you are unsure whether a change is minor or serious, this guide on cat skin bumps and lumps can help you decide when to call your vet.
What you may see on the ears
Skin cancer in cats' ears often starts as a small crusty area on the edge or tip of the pinna, the flap of the ear. It may look like a scab that never heals, a red patch, or a sore that bleeds when scratched. In one reported case, a cat had long-standing crusty skin lesions on the ear flaps, neck, and belly that had persisted for years before diagnosis [3]. Ear lesions are easy to miss because cats often scratch at them and owners assume it is just irritation.
What you may see on the nose
Skin cancer in cats' nose commonly appears on the planum, the leathery part of the nose, or along the bridge. You might notice a pink or red area, a sore that oozes, or a change in the texture of the nose leather. Because the nose is thin-skinned and close to bone and cartilage, tumors here can become painful and can erode tissue if left untreated.
General signs of skin tumors in cats
- A firm, solitary lump that may be hairless or ulcerated [1]
- A lump that sticks out from the skin like a stalk [1]
- Dark-colored growths, which are common with basal cell tumors in cats [1]
- A sore that bleeds, crusts, or refuses to heal
- Swelling or redness around the eyes or eyelids
- Drooling, bad breath, or trouble eating if a tumor is near the mouth
Basal cell tumors can range from less than 0.4 inches (1 centimeter) to more than 4 inches (10 centimeters) across [1]. Some grow quickly and cause extensive ulceration and inflammation even though they are benign [1].
Causes and Risk Factors
Several factors can cause skin tumors in cats, including chemical carcinogens, solar radiation, and viruses [1]. Hormonal and genetic factors may also play a role [1].
Sun exposure
Ultraviolet light from the sun damages skin cells, especially on lightly pigmented and thinly haired areas. The ears, nose, and eyelids get the most sun, which is why tumors cluster there. White cats and cats with white faces are at higher risk.
Breed and genetics
Basal cell tumors are most common in Domestic Longhair, Himalayan, and Persian cats [1]. If your cat is one of these breeds and develops a lump, mention the breed history to your vet.
Viruses
Feline papillomaviruses have been linked to some skin cancers. One cat with multicentric squamous cell carcinoma in situ was found to be coinfected with two different feline papillomaviruses, Felis catus papillomavirus type 7 and a previously unknown type [3]. This does not mean every cat with papillomavirus will develop cancer, but it shows that viral infection can contribute.
Age
Skin tumors are more common in older cats. Basal cell tumors in particular are described as common in older cats [1].
How Vets Diagnose Skin Cancer in Cats
Diagnosis starts with a physical exam and a history of when you first noticed the change. Your vet will look at the size, color, texture, and location of the lesion and check the rest of the skin for other spots.
Fine needle aspiration
A thin needle is used to collect cells from the lump. This is quick and often done without sedation. It can suggest whether a growth is a cyst, an infection, or a tumor, but it does not always give a final answer.
Biopsy
A biopsy removes a piece of tissue for examination under a microscope. This is the standard way to confirm skin cancer. In the papillomavirus case, biopsies from the neck and abdomen revealed multicentric squamous cell carcinoma in situ confined to the epidermis [3]. Biopsy results tell your vet the tumor type, how aggressive it looks, and whether it is benign or malignant.
Staging tests
If cancer is confirmed, your vet may recommend blood work, imaging, or lymph node checks to see whether the tumor has spread. Staging helps guide treatment. In a study of cats with cutaneous SCC treated with electrochemotherapy, tumors were classified as early stage (T1 to T2) in 31.4 percent of cats and advanced stage (T3 to T4) in 68.6 percent [2].
Treatment Options for Skin Cancer in Cats
Treatment depends on the tumor type, size, location, and stage, plus your cat's overall health. Your vet will calculate any drug dose from your cat's weight and health status.
Surgery
Surgical removal is an effective treatment for basal cell tumors [1]. For malignant tumors, surgery aims to remove the entire growth with a margin of normal tissue. Tumors on the ear tip may be removed with part of the ear, while tumors on the nose can be more complicated because of the limited tissue available.
Electrochemotherapy
Electrochemotherapy (ECT) combines a chemotherapy drug with electrical pulses that help the drug enter tumor cells. In a study of 35 cats with cutaneous SCC, ECT produced an objective response in 100 percent of cats, with 65.7 percent achieving complete response and 34.3 percent achieving partial response [2]. Median overall survival was 300 days, and median progression-free survival was 285 days [2]. The median tumor diameter was 2.3 centimeters, and tumors larger than that were linked to a higher chance of toxicity [2]. ECT has also been used for tumors in the mouth, where it preserved eating and drinking in one reported cat [6].
Photodynamic therapy
Photodynamic therapy (PDT) uses a light-activated drug applied to the tumor. In one cat with squamous cell carcinoma on both eyelids, PDT alone resolved the lesion on the left eye, and PDT followed by ECT produced significant regression on the right eye [4]. This approach can preserve eyelid function, which matters for blinking and eye health.
Topical medication
Some surface-level cancers respond to creams that stimulate the immune system. A cat with multicentric squamous cell carcinoma in situ was treated with topical imiquimod cream twice weekly for 3 months and went into complete clinical remission [3]. Two mild recurrences on the neck were controlled with a short repeat course, and the cat remained well over 1.5 years of follow-up [3].
Other options
Radiation and chemotherapy may be used for certain tumors, depending on the case. Your vet will discuss whether these are appropriate for your cat.
| Treatment | Best suited for | What to expect |
|---|---|---|
| Surgery | Benign tumors, small malignant tumors | Often curative for basal cell tumors [1] |
| Electrochemotherapy | Cutaneous SCC, oral tumors | 100% response rate in one study, median survival 300 days [2] |
| Photodynamic therapy | Eyelid and surface tumors | Preserves function, may need repeat sessions [4] |
| Topical imiquimod | Carcinoma in situ | Complete remission reported in one case [3] |
Recovery, Outlook, and Long-Term Management
The outlook for cat skin cancer varies widely. Benign tumors removed completely usually do not come back. Malignant tumors depend on stage, size, and location.
For cutaneous SCC treated with ECT, median overall survival was 300 days and median progression-free survival was 285 days [2]. That means half the cats in that study lived longer than 300 days and half lived less. Some cats do much better, especially with early-stage tumors.
Tumor size matters. In the ECT study, tumors larger than 2.3 centimeters were associated with more toxicity [2]. Smaller tumors at diagnosis tend to have better outcomes.
Location matters too. SCC in the mouth is aggressive. Feline oral squamous cell carcinoma is the fourth most common malignant tumor in cats, and most cats are not treated because of the poor prognosis, dying of the disease within a few months of diagnosis [7]. SCC in the trachea is rare and has a poor prognosis with limited treatment options [8]. Skin SCC on the ears and nose is generally more treatable than SCC inside the body.
After treatment, your vet will want regular rechecks. Take photos of the original lesion so you can compare. Watch for new lumps, changes in old ones, weight loss, or trouble eating. If your cat has other skin conditions, such as a cat skin infection or hair loss with red skin, those need separate management and can complicate monitoring.
Prevention
You cannot prevent every skin tumor, but you can lower risk and catch problems early.
- Limit sun exposure for white cats and cats with thin hair on the ears and face. Keep them indoors during peak sun hours.
- Use pet-safe sunscreen on the ear tips and nose if your vet approves it. Never use zinc oxide products on cats.
- Check your cat's ears, nose, eyelids, and belly once a month. Feel for lumps and look for crusts or sores.
- Book a vet visit for any sore that has not healed in two to three weeks.
- Keep up with routine wellness exams, especially as your cat ages.
Limitations and When to Contact a Veterinarian
No article can tell you whether your cat's specific lump is cancer. Only a veterinarian can examine, sample, and diagnose it. Individual cases need a veterinarian's hands-on assessment.
Contact your vet the same day if you notice:
- A new lump that is growing quickly
- A sore on the ear, nose, or eyelid that bleeds or will not heal
- Swelling around the eye or a change in how the eye looks
- Bad breath, drooling, or dropping food while eating
Go to an emergency clinic now if your cat:
- Has trouble breathing
- Cannot eat or drink
- Has sudden severe swelling around the face or neck
- Is lethargic and not responding to you
Schedule a routine visit soon if you find a small lump that is not changing, or if you want a baseline check on an older cat.
Frequently Asked Questions
Are lumps on a cat's ear always cancer?
No, many lumps are benign. Basal cell tumors are common in older cats and are benign, though they can grow and ulcerate [1]. Only a biopsy can tell you for certain what a lump is.
Can skin cancer in cats be cured?
Some can. Basal cell tumors are usually cured with surgery [1]. Some squamous cell carcinomas, especially small ones on the ears or nose, can be controlled or cured with surgery, electrochemotherapy, or photodynamic therapy [2][4].
Does my cat need surgery for skin cancer?
Not always. Surgery is one option, but electrochemotherapy, photodynamic therapy, and topical medications have all produced good results in reported cases [2][3][4]. Your vet will recommend the approach that fits your cat's tumor and health.
How fast does skin cancer spread in cats?
It varies by tumor type. Oral squamous cell carcinoma is aggressive, and most cats die of the disease within a few months of diagnosis [7]. Skin tumors on the ears and nose tend to be slower and more treatable.
Should I put sunscreen on my cat?
Only with your vet's guidance, and only pet-safe products. Human sunscreens, especially those containing zinc oxide, can be toxic to cats if licked off. Keeping your cat out of direct sun is safer and simpler.
Related Articles
- Cat Skin Infection: Signs and Treatment Options
- Cat Hair Loss with Red Skin: Causes and Treatment
- Cat Skin Bumps and Lumps: When to See a Vet and When to Monitor
- Feline Hyperthyroidism: Signs, Diagnosis, and Treatment
- Feline Feline Mammary Tumors: Diagnosis and Management
- Cat Stock Photography: What Images Reveal About Feline Health
References
- Tumors of the Skin in Cats - Cat Owners. Merck Veterinary Manual.
- Prognostic factors in cats with squamous cell carcinoma treated with electrochemotherapy. Veterinary journal (London, England : 1997), 2026.
- Coinfection with Different Feline Papillomaviruses in a Cat with Multicentric Squamous Cell Carcinoma In Situ. Animals : an open access journal from MDPI, 2026.
- Sequential Photodynamic Therapy and Electrochemotherapy for Bilateral Palpebral Squamous Cell Carcinoma in a Cat: A Case Report. Veterinary ophthalmology, 2026.
- Feline Skin Diseases. Cornell University College of Veterinary Medicine.
- Electrochemotherapy for feline lingual squamous cell carcinoma: a case report of functional preservation as a palliative approach. Frontiers in veterinary science, 2026.
- Whole Exome Sequencing of Feline Oral Squamous Cell Carcinoma Reveals Genomic Parallels With Human Head and Neck Squamous Cell Carcinoma. Veterinary and comparative oncology, 2026.
- Tracheal Squamous Cell Carcinoma in an Adult Cat. Veterinary radiology & ultrasound : the official journal of the American College of Veterinary Radiology and the International Veterinary Radiology Association, 2026.