CONDITION
Squamous Cell Carcinoma of the Nasal Planum
Squamous cell carcinoma of the nasal planum is a type of skin cancer that arises from the flat cells lining the surface of the nose leather—the hairless, pigmented area at the tip of a dog's or cat's nose. These tumours grow locally, often beginning as a small rough patch or persistent sore that does not heal, and over time can erode into the surrounding tissue. They tend to occur in older animals and are more common in those with lighter or unpigmented skin on the nose, particularly in cats. Owners often notice a change in the appearance of the nose itself: a crusted area, a raised or ulcerated lesion, occasional bleeding, or a gradual loss of the normal smooth texture. The lesion may be present for weeks or months before prompting concern, and it can be mistaken for an injury, infection, or allergic reaction at first. In cats, these changes are sometimes subtle and progress slowly. This page explores the signals that may raise suspicion, what is happening in the tissue beneath the surface, how the condition is investigated through biopsy and imaging, and the range of approaches—surgical, radiation-based, and supportive—that may be considered depending on the extent and location of the tumour.
Why this matters now
Squamous cell carcinoma of the nasal planum tends to appear in middle-aged to older animals, most commonly in cats over ten years of age and dogs over eight. Animals with white or lightly pigmented nose leather are at higher risk, as the lack of melanin offers less protection against cumulative ultraviolet exposure. In cats particularly, this tumour is one of the more frequently encountered malignancies affecting the head, and chronic sun exposure appears to play a significant role in its development.
The condition often begins as a small area of roughness or colour change that persists for weeks or months without obvious cause. Over time, the affected tissue may thicken, crack, or ulcerate, and the lesion can gradually expand across the surface of the nasal planum or erode deeper into underlying cartilage and bone. The rate of progression varies considerably between individuals; some lesions advance slowly over many months, whilst others enlarge more noticeably within weeks. Left undisturbed, local invasion tends to continue, though distant spread to other organs is uncommon in this particular form of the disease.
Signals & patterns
Early signals
Persistent rough or crusty patch
A small area on the nose that feels rough to the touch or develops a scaly, crusty surface that does not resolve with time. This may be mistaken for a minor scrape or dry skin at first, but it remains present despite normal grooming or cleaning.
Loss of pigment or texture change
A previously smooth, evenly coloured nose may develop a pale or mottled patch, or the surface may lose its usual moist, slightly bumpy texture. The change can be subtle and may be noticed only when comparing recent photographs or during routine close inspection.
Occasional minor bleeding or scabbing
The nose may bleed lightly after the animal sniffs or nuzzles against surfaces, or a small scab may form and then detach repeatedly. Owners sometimes attribute this to a knock or scratch, but the pattern recurs in the same location.
Small raised or thickened area
A portion of the nasal planum may appear slightly raised, firmer than the surrounding tissue, or develop a small nodule or plaque. This thickening can be felt when gently touching the nose and may enlarge slowly over weeks.
Later signals
Ulcerated or eroded lesion
The surface of the nose develops an open sore or crater that does not heal, often with irregular edges and a raw, exposed base. The lesion may bleed more readily and can become encrusted with dried blood or discharge.
Swelling or deformity of the nose
As the tumour invades deeper tissue, the shape of the nasal planum may change, becoming swollen, asymmetrical, or visibly distorted. The nose may feel firmer or bulkier than before, and the nostrils can become narrowed or displaced.
Nasal discharge or difficulty breathing
If the tumour erodes into the nasal passages, a discharge—sometimes clear, sometimes tinged with blood—may appear from one or both nostrils. Breathing through the nose may become audible or laboured, particularly during rest or in warm conditions.
Click to read about the biological mechanisms
How this is usually investigated
Options & trade-offs
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