Squamous Cell Carcinoma in Pigs: Skin Cancer Warning Signs

Squamous cell carcinoma, often shortened to SCC, is a malignant cancer that starts in squamous cells. These are the flat cells that make up the outer layers of skin and some mucocutaneous surfaces. In pigs, SCC is considered uncommon, but it is important because it can be locally invasive and destructive if it is not found early.

This cancer often begins as a chronic-looking skin lesion rather than a dramatic lump. A pet parent may notice a scab that keeps returning, a rough plaque, a wart-like growth, or an ulcer that bleeds when rubbed. In veterinary species, squamous cell carcinoma is strongly associated with chronic solar injury in lightly pigmented skin, and pigs with white or spotted skin can also be prone to sunburn on exposed areas.

Many SCC lesions spread locally into nearby skin and tissue before they spread to distant sites. That means timing matters. A smaller lesion may be easier for your vet to remove completely, while a larger lesion can require a wider surgery and more aftercare.

Because pigs can hide discomfort, even a lesion that seems minor deserves attention if it is persistent. If a skin sore has not healed within 2 to 3 weeks, or it keeps crusting, cracking, or bleeding, it is reasonable to schedule an exam with your vet.

There is not always one single cause, but chronic ultraviolet light exposure is a major concern for squamous cell carcinoma across veterinary species. Merck Veterinary Manual notes that solar injury can lead to SCC in lightly pigmented skin, and VCA notes that white or spotted mini-pigs are more likely to develop sunburn on exposed areas. Repeated sun damage can set the stage for precancerous skin change and, over time, malignant transformation.

Pigs with pale or nonpigmented skin are thought to be at higher risk than pigs with darker, more protective pigmentation. Areas with sparse hair coverage are also more vulnerable. In pigs, the ears, nose, back, and nipples are known sun-sensitive sites, and any chronically irritated pale skin deserves monitoring.

Age may also matter. In many species, SCC is more common in adults and seniors because sun damage and cellular injury build up over time. Chronic inflammation, repeated trauma, and possibly viral or immune-related factors may contribute in some cases, but these links are less clearly defined in pigs than the role of solar injury.

It is also important to separate SCC from other sun-related skin problems. Sunburn and photosensitization can both cause redness, pain, crusting, and ulcers on nonpigmented skin. Those conditions do not automatically mean cancer is present, but they can look similar early on, which is one reason your vet may recommend a biopsy instead of guessing.

Diagnosis starts with a hands-on exam and a careful history. Your vet will want to know how long the lesion has been present, whether it has changed in size, whether it bleeds or drains, and how much sun exposure your pig gets. Photos over time can be very helpful because they show whether a lesion is stable or progressively enlarging.

A fine-needle aspirate may be used for some masses, but skin cancers like SCC often need a biopsy for a clear answer. That means your vet removes a small tissue sample, or sometimes the whole lesion if it is small enough, and sends it to a pathology lab. Histopathology confirms whether the lesion is SCC and helps show how aggressive it appears and whether the sample edges are clean if the whole mass was removed.

If the lesion is large, fixed to deeper tissue, near the eye or mouth, or has been present for a long time, your vet may also recommend staging tests. These can include bloodwork, lymph node evaluation, and imaging such as radiographs or ultrasound to look for deeper invasion or spread. Not every pig needs every test. The workup should match the lesion, your pig's comfort, and your goals for care.

Because pigs can be stressed by transport and restraint, sedation may be part of the plan for biopsy or imaging. Your vet can help balance diagnostic value, safety, and budget so you can choose an approach that fits your pig's situation.

Prevention focuses on reducing chronic sun damage and catching suspicious lesions early. Pigs with white, pink, or spotted skin need reliable shade whenever they are outdoors. VCA notes that white or spotted mini-pigs are prone to sunburn, and sunburned areas in pigs commonly affect the ears, nose, back, and nipples. Limiting midday sun exposure is a practical first step.

Talk with your vet about safe barrier strategies for your pig. In some cases, your vet may recommend a pet-safe sunscreen for exposed pale skin, but products should be chosen carefully because some human sunscreens can cause stomach upset or other problems if licked. Shade structures, indoor access during peak sun, and avoiding long periods on reflective surfaces can all help.

Routine skin checks matter. Once a week, look over the ears, nose, eyelids, back, belly, and any pale skin for redness, crusting, thickening, ulcers, or new growths. Taking a phone photo with the date can help you track subtle changes. A lesion that is not healing is more important than a lesion that is dramatic.

Finally, treat recurring sunburn and chronic skin irritation as medical issues, not cosmetic ones. Early veterinary attention for persistent sores may allow a smaller biopsy, a smaller surgery, and a better outcome. Prevention is not always perfect, but earlier detection usually gives you more options.