When to see a vet urgently
Contact a vet promptly if your cat's skin has any of these changes:
- a very tender, blistered or extensively broken area;
- a bleeding wound, increasing swelling or discharge containing pus on an ear or the muzzle;
- a repeatedly reopening scab or a wound that does not heal;
- a new, growing lesion on an ear tip, the nose or an eyelid.
Severe pain and extensive burns need immediate assessment. Do not watch even a small recurring scab until the following summer. You can find a vet near you.
Overview
Ultraviolet rays damage skin cells, causing inflammation, scaling and ulcers. Pale cats are particularly susceptible because their skin lacks enough pigment to protect it from the sun. Solar dermatitis is often diagnosed in cats that spend a lot of time outdoors or enjoy sunbathing on a windowsill.
Sun damage does not always mean one clearly observed episode of sunburn. Exposure can accumulate through repeated time in the sun even if you have never seen blisters. Ultraviolet radiation can also damage cells' genetic material, or DNA. Abnormal multiplication of damaged cells is associated with the development of precancerous changes and tumours.
Actinic keratosis means a change in the keratinisation of sun-damaged skin. In superficial carcinoma in situ, cancer cells have not yet invaded deeper supporting skin tissue. Invasive squamous cell carcinoma penetrates surrounding tissues. Not all redness is cancer, but these stages cannot be reliably distinguished by looking at home.
Causes
- prolonged exposure to direct sunlight;
- lack of skin pigment, with white fur and pink ears and nose;
- reduced immunity and weakened protective properties of the skin;
- chronic skin inflammation.
Direct UV exposure is the main cause of solar dermatitis. Less is known about the independent effects of reduced immunity and chronic inflammation specifically on feline solar dermatitis risk. They do not alone establish sun damage, and similar-looking skin changes may have another cause. Not every form of squamous cell carcinoma is sun-related either.
Risk factors
- white and pale-coated cats;
- cats living in sunny areas;
- cats that go outdoors;
- cats that enjoy sunbathing on a windowsill or balcony.
The pigment and fur protection of the particular skin area matter especially, rather than the colour of the whole coat alone. Even a dark-coated cat may have a pale or sparsely haired area. A white cat needs skin protection before visible changes appear, because cancer risk cannot be assessed from the severity of the latest sunburn alone.
Tell the vet about an indoor cat's sunbathing habits too. A sunny window spot used for a long time or a balcony resting place forms part of the exposure history. Planning shade and, where necessary, UV protection for windows may be needed even if your cat does not roam outdoors.
Typical symptoms
- skin redness and scaling;
- hair loss on the ears, nose and eyelids;
- scabs and ulcers;
- tenderness when touched;
- a chronic course that worsens in summer;
- malignant change to squamous cell carcinoma in severe cases.
Initially, an ear tip may look only slightly red, scaly or thinned. Later, the surface may become crusty, break down and bleed. A concerning lesion may be small while the cat remains generally well. Continuing to eat and play therefore does not rule out a local skin tumour.
A recurring scab may fall off, making the skin briefly look better. If another scab develops in the same place, it may not be a healed scratch. Photograph the change and record its location, duration and recurrence for the veterinary visit. Scabs do not themselves prove a solar cause.
Similar redness, hair loss and ulceration can occur with parasites, fungal infection or other inflammation, for example. Outdoor activity, previous skin disease and products used are therefore investigated too. Solar dermatitis is not diagnosed simply because a cat is white.
Complications and consequences
- chronic ulcers and skin necrosis;
- secondary bacterial infections;
- cutaneous squamous cell carcinoma, a common complication of prolonged sun exposure;
- disfiguring damage to the ears and nose.
Prolonged exposure increases the risk of squamous cell carcinoma, but not every case of solar dermatitis becomes cancer. An individual cat's progression risk cannot reliably be expressed as a general percentage. Examination aims to identify both treatable inflammation and any tumour early enough.
Tissue damage to the ears and nose is more than a cosmetic problem. Ulceration can cause pain, and a tumour can gradually destroy local structures. Cutaneous squamous cell carcinoma often progresses mainly locally; distant spread may be slower than tissue destruction at the original site. Slow development of metastases therefore does not make the tumour harmless.
Diagnosis at the vet
- a clinical examination;
- skin tests to rule out fungal and parasitic disease;
- a skin biopsy if precancerous or tumour changes are suspected;
- cytological examination of impression smears.
Sampling clarifies an uncertain lesion
The vet examines the rest of the skin as well as the lesion and checks whether several areas are affected. An impression smear collects cells and discharge from the surface onto a slide. It may help identify inflammation or organisms, but often samples mainly superficial inflammatory discharge. It does not always show what is happening deeper in the tissue.
A tissue sample, or biopsy, also provides information on skin architecture and possible invasion of surrounding tissue by abnormal cells. It is examined under a microscope in a laboratory. Sampling, pain relief or anaesthesia are planned according to location and the cat's condition. Clinical suspicion and an inconclusive cell sample may therefore lead to a biopsy.
If a malignant tumour is diagnosed, its size, depth and, where needed, spread are assessed. Nearby lymph nodes may be sampled, for example. Other tests are chosen according to the finding and planned treatment; mild skin redness alone does not require every test.
Treatment and follow-up
Treating inflamed skin
Keep your cat out of the sun so further exposure does not maintain the damage. The vet selects pain relief, topical treatment and wound protection if needed. Severe burns may need broader supportive care. Bacterial infection is treated according to findings; antibiotics do not remove UV damage or a possible tumour.
Scratching and rubbing can damage the skin further. Ask the practice how to prevent this safely. Leave scabs alone and do not apply your own medicated creams or cleaning chemicals. A lesion near the eye also requires treatment suitable for that location.
If the finding is precancerous or a tumour
Treatment choice depends on location, extent and the biopsy result. A small superficial lesion can sometimes be treated locally, for example by freezing. Diagnosed squamous cell carcinoma is often treated surgically, aiming to remove the entire lesion with a margin of healthy tissue. Radiotherapy may be considered for some sites.
Removing an ear tumour may require removal of part of the ear flap. On the nose and eyelids, preserving surrounding structures is weighed against tumour control. An early superficial lesion is usually easier to manage than a tumour that has invaded deep tissue.
After treatment, monitor healing and new skin lesions. A recurring wound or a similar change elsewhere needs further investigation. Continue sun protection after successful local treatment too. Temporary disappearance of symptoms is not a reason to return to prolonged daily sunbathing.
Prevention
- Limit time in the sun during the strongest sunshine, approximately 10:00–16:00, particularly during long summer days.
- Use a safe animal sunscreen according to veterinary advice.
- Provide shady places indoors and outdoors.
- Check the skin of at-risk cats regularly.
Clock times are only a rough guide. UV protection may be needed beyond this window, so a fixed 10:00–16:00 limit does not cover every situation. Radiation varies with location, season and weather. Cool conditions or thin cloud do not guarantee low UV exposure.
The UV index can inform plans for outdoor time, but a protection threshold announced for people is not an established safe exposure limit for feline skin. Previously sun-damaged, unpigmented skin needs individual protection. Shade reduces direct radiation, although scattered and reflected radiation may still reach the area.
Check that a sunscreen is suitable specifically for cats, as cats lick their skin and animal products do not all have the same ingredients. Do not choose a human product yourself; creams containing salicylates or zinc oxide, for example, should be avoided. Sunscreen complements limiting exposure and does not justify longer sunbathing.
Provide a comfortable resting place in shade both indoors and in an outdoor enclosure. A sunny window may need shading or UV protection. Also check how the sun moves during the day: a bed shaded in the morning may later be in direct sunshine.
Important for cat owners
Solar dermatitis is a common problem in white and pale cats. Remember that it is more than a sunburn: it is chronic damage that can eventually become skin cancer. Early detection and sun protection help preserve your cat's health and life.
This article provides general information and does not replace veterinary care. If you notice signs of illness in your cat, contact a vet.
Frequently asked questions
Can an indoor cat develop sun damage?
Yes. The skin and exposure of a cat using a sunny window spot also need assessment. Time at the window can be limited with shading or UV protection. Monitor unpigmented ears and nose in indoor cats too.
Is a small scab on the ear definitely skin cancer?
No, but a recurring or poorly healing scab needs investigation. Inflammation, injury and a tumour can look similar. A tissue sample can establish the nature of the change if needed.
Is sunscreen enough to protect my cat?
Not alone. Avoiding excessive exposure and providing shade are the basis of protection. A cat may lick sunscreen off, and a safe product is chosen with the vet. An existing wound or tumour is not treated with sunscreen alone.
This article is for general information only and is not a guide to treatment. If you notice the first signs of illness, contact your vet.
Paw4care editorial team
Sources
- Epidermal and Hair Follicle Tumours in Animals, Merck Veterinary Manual, accessed 2026-11-03.
- Squamous Cell Cancer: Dangerous, Cornell Feline Health Centre, accessed 2026-11-03.
- Squamous Cell Carcinomas in Cats, VCA Animal Hospitals, accessed 2026-11-03.
- Cats and Warm Weather, Cats Protection, accessed 2026-11-03.
- Sunburn in Pets, PDSA, accessed 2026-11-03.
- UV-säteily, Ilmatieteen laitos, accessed 2026-11-03.
- Cytology, Merck Veterinary Manual, accessed 2026-11-03.