Squamous Cell Carcinoma in Dogs
Key takeaways
Squamous cell carcinoma (SCC) is a malignant tumor formed of keratinocytes, a type of skin cell.
- SCCs are often characterized by the location of the tumor (e.g. oral, digital, etc.)
- SCC tumors usually appear as a raised, irritated, ulcerated, or red mass on the skin
- Biopsy is necessary to confirm the diagnosis, and affected dogs typically undergo a full workup with blood tests and diagnostic imaging to look for potential metastasis and determine overall health status
- Treatment primarily involves surgical removal of the tumor
- Other treatment options include chemotherapy, topical medications, palliative care, and euthanasia in severe cases
- SCC has one of the best prognoses compared to other types of canine cancer if it is diagnosed before metastasis
- Surgical removal of small, non-metastatic SCC tumors is often curative
Connect with a vet to get more information about your pet’s health.
A closer look: Squamous Cell Carcinoma in Dogs
SCCs can be categorized into the locations in which they appear. These can have different associated symptoms.
Many SCC tumors do not show any other symptoms. They are usually not itchy. These tumors are painful in some, but not all, cases. Ulcerated tumors may develop secondary infections with associated symptoms:
- Redness
- Heat
- Swelling
- Discharge
- Foul odor
Connect with a vet to get more information
Risk factors
SCC is not a common condition in dogs overall, but it is a common type of canine cancer. It is more common in older dogs and is seen more often in Scottish Terriers, Pekingese, Boxers, Poodles, and Norwegian Elkhounds. It is also seen more frequently in dogs with thinner or lighter colored coats than those with dark or heavy coats, especially if they spend a lot of time outdoors in areas with heavy UV exposure.
SCC tumors are rarely metastatic and are not often fatal, especially if caught early and treated. Treatment can be difficult and time-consuming, and may require referral to a veterinary oncologist.
Possible causes
A genetic predisposition is suggested, but some cases are idiopathic, meaning no cause can be identified.
Main symptoms
Most SCCs appear as a raised, red mass on the skin or in the mouth, arising from the gumline or the back of the throat. The affected skin may be confused for a rash or injury and may bleed or be ulcerated. The tumors are most often seen in the mouth, on the nose, perianal region, belly, and toes. This appearance is not exclusive to SCC or even cancer, so a biopsy is necessary to confirm diagnosis.
Testing and diagnosis
After a physical examination, a biopsy is needed to determine the diagnosis. Additional tests, urine/blood analysis and diagnostic imaging, are performed to determine the overall health status of the dog and to look for signs of metastasis.
Steps to Recovery
Once squamous cell carcinoma is identified, treatment varies based on progression of the cancer and location of the tumor. Treatments include:
- Topical therapy
- Surgery
- Chemo
- Radiation
- Cryotherapy
- Photodynamic therapy
- Palliative care/symptom management
- Euthanasia
SCC is often very locally invasive, but the prognosis is generally favorable with early identification and aggressive treatment since it is usually not metastatic. SCC on the nasal planum (hairless part of the nose) is more difficult to manage and carries a guarded prognosis.
If metastasis has occurred, prognosis is much worse. SCC typically metastasizes to the lymphatic system or lungs where it is more complicated to treat and manage.
Prevention
Strategies to prevent SCC include:
- Minimizing sun exposure
- Maintaining good skin hygiene
- Monitoring regularly for changes to the skin
Squamous cell carcinoma is not contagious.
Is Squamous Cell Carcinoma in Dogs common?
Squamous cell carcinoma is not a common condition overall in dogs, but it is one of the more common canine cancers.
Typical Treatment
- Topical therapy
- Surgery
- Chemo
- Radiation
- Cryotherapy
- Photodynamic therapy
- Palliative care/symptom management
- Euthanasia
