CONDITION

Squamous Cell Carcinoma in Cats

Squamous cell carcinoma in cats commonly affects sun-exposed areas like the ears and nose, particularly in white-coated individuals, developing from precancerous changes to invasive cancer. A separate form arises in the mouth, where it is the most common oral tumour in cats and carries a much poorer outlook.

Why this matters now

This cancer typically develops in middle-aged to older cats, often after years of cumulative sun exposure. White cats or those with unpigmented skin on their ear tips and nose are particularly susceptible. Early lesions may be mistaken for minor wounds before progressing.

The condition usually begins as subtle crusty or scaly patches that fail to heal. Over months, these areas can deepen and expand, eventually becoming ulcerated masses that erode underlying tissue.

Signals & patterns

Early signals

Persistent crusting on ear tips

Scaly patches that recur after healing may represent precancerous changes.

Non-healing nose lesions

Small sores on unpigmented areas of the nose that fail to resolve.

Reddened skin margins

Inflammation around white-furred ear edges or nasal areas.

Subtle thickening

Affected skin may feel slightly thicker or firmer than normal.

Later signals

Ulcerated masses

Open, bleeding wounds that progressively enlarge.

Tissue destruction

Erosion of ear tips or nasal tissue becomes visible.

Facial swelling

Advanced oral or nasal cases may cause visible facial asymmetry.

Difficulty eating

Oral squamous cell carcinoma can cause drooling, bad breath, reluctance to eat and bleeding from the mouth. The mass is often under the tongue or at the back of the mouth, where it cannot be seen at home.

Click to read about the biological mechanisms

How this is usually investigated

Diagnosis requires tissue sampling to confirm the cancer type, with imaging helping assess local invasion and lymph node involvement.

Biopsy

Purpose: Confirms diagnosis and determines cancer grade through microscopic examination
Considerations: Needed to confirm the diagnosis. Sampling the nose usually needs a general anaesthetic because the area is sensitive, and masses in the mouth are often sampled under general anaesthetic so that a good sample can be taken.

Fine needle aspirate

Purpose: Quick sampling of suspicious masses or enlarged lymph nodes
Considerations: Less invasive than biopsy; may not always provide enough tissue for complete diagnosis.

CT scan

Purpose: Assesses extent of bone involvement in nasal or oral cases
Considerations: Important for surgical planning; requires anaesthesia; reveals invasion depth.

Chest radiographs

Purpose: Screens for spread to lungs in advanced cases
Considerations: Lung metastasis uncommon for cutaneous form but important to check.

Lymph node assessment

Purpose: Evaluates regional lymph nodes for cancer spread
Considerations: Part of staging for both forms; guides prognosis and treatment planning.

Options & trade-offs

Treatment approaches depend on tumour location, extent, and whether complete removal is achievable, ranging from surgery to radiation or combined modalities.

Surgical excision

Removal of tumour with margins of normal tissue

Trade-offs: Often curative for early skin lesions, though regrowth can follow; may require ear tip or nose tip amputation; cosmetic change. In the mouth, complete removal is rarely possible and regrowth is common.

Radiation therapy

Targeted radiation to destroy cancer cells

Trade-offs: Useful when surgery incomplete or declined; multiple sessions; local side effects during treatment.

Cryosurgery

Freezing of small superficial lesions

Trade-offs: Minimally invasive for early lesions; less effective for larger tumours; may require repeat treatments.

Photodynamic therapy

Light-activated treatment for superficial cancers

Trade-offs: Non-surgical option; limited availability; suitable only for early lesions.

Palliative care

Comfort-focused approach for advanced disease

Trade-offs: Appropriate when curative treatment not possible; maintains quality of life; variable duration.

Common misconceptions

Misconception:

"Indoor cats cannot develop sun-related skin cancer"

Reality:

Cats that sunbathe in windows receive UV exposure that can contribute to squamous cell carcinoma development.

Misconception:

"A crusty ear is just a minor wound"

Reality:

Persistent or recurring crusty lesions on ear tips of white cats often represent precancerous or early cancerous changes.

Misconception:

"Removing part of the ear is cruel"

Reality:

Cats adapt well to partial ear amputation, and early surgery often provides the opportunity for cure.

Related conditions

Squamous Cell Carcinoma of the Pinna in Cats

The ear tips are among the most common sites of sun-related squamous cell carcinoma in cats, particularly in white cats, and early ear tip lesions can often be removed by partial ear amputation.

Squamous Cell Carcinoma of the Nasal Planum

The nose is another common site of sun-related squamous cell carcinoma in cats. Lesions here are harder to remove completely than those on the ear tips.

Oral Squamous Cell Carcinoma in Cats

Squamous cell carcinoma in the mouth is the most common oral tumour in cats. It commonly invades bone and has a much poorer outlook than the skin form.

Feline Stomatitis

Stomatitis can cause drooling, bad breath, mouth pain and reluctance to eat, like oral squamous cell carcinoma, so a biopsy may be needed to tell them apart.

Owners of white cats or those with unpigmented facial skin may find value in monitoring for persistent skin changes. Understanding that early lesions offer more treatment options than advanced disease can inform decisions about when to seek evaluation.

Last reviewed: 9 October 2026 · Dr Alastair Greenway MRCVS