What is Skin Cancer (Squamous Cell Carcinoma)?
A squamous cell carcinoma is a cancer of the epidermal cells in the skin of dogs. This is a malignant tumor, but metastasis to other parts of the body is rare, especially with cutaneous tumors. Squamous tumors account for only about 5% of all cutaneous tumors in dogs. Subungual squamous tumors in the nail bed are more common and have a higher rate of metastasis to the lymph nodes and lungs. Most tumors appear as a raised lump with a rough surface resembling a wart. Tumors are usually inflamed and may bleed and become infected, especially if a dog scratches or digs at the tumor. Concurrent bacterial or fungal infection is possible, and the local lymph nodes often become inflamed, depleting the immune system, and making it easier for the cancer to metastasize. Subungual tumors on the nail bed often result in loss of the nail, and dogs may show signs of limping and lameness. These tumors may spread into bone and the nerve cells and are more difficult to remove permanently with surgery than cutaneous tumors. Squamous tumors can also occur in the epithelial layer of the gastrointestinal tract, especially in the oral cavity. Depending on the location of the tumor, oral squamous carcinoma can interfere with swallowing or cause mild cough. Tumors on the tonsils and tongue have a higher rate of metastasis, while those in the nasal cavity are more likely to remain contained. Surgery is frequently an effective treatment for squamous cell carcinomas, unless metastasis to the lungs or lymph nodes is already present at the time of diagnosis.
Cancerous tumors that form on the epidermal layer of the skin are called squamous cell carcinoma. This type of tumor can be found in several locations, either directly on the skin, in the nail bed area of the toes, or in the oral cavity. Squamous cell carcinoma has a low rate of internal metastasis, so it is more treatable than many other forms of cancer.
Symptoms of Skin Cancer (Squamous Cell Carcinoma) in Dogs
Symptoms may vary depending on the location of the tumor.
- Raised wart like lump
- Inflamed sores
- Bleeding sores
- Limping or signs of pain when walking
- Lameness
- Excessive drooling
- Difficulty chewing or swallowing
- Mild cough
- Swollen or inflamed areas in the mouth
- Loose teeth
- Oral bleeding
Types
Squamous cell carcinomas are defined by their location on the body.
Cutaneous squamous cell carcinoma (actinic keratosis)
- Tumors that occur in the skin especially hyper-pigmented areas with a high rate of exposure to sunlight
- More common in Keeshonds, Standard Schnauzers, Basset Hounds and Collies.
Subungual squamous cell carcinoma
- Tumor in the epithelial layer of the nail bed, this is the most common form of squamous cell carcinoma, accounting for about 50% of digital tumors in dogs
- A slightly higher number of females are affected
- Breeds with increased incidence include Giant, Standard and Miniature Schnauzers, Gordon Setters, Standard Poodles, Scottish Terriers, Labrador Retrievers, Rottweilers, and Dachshunds
Oral Squamous cell carcinoma
- Squamous tumor that occurs in the mouth, more common in older neutered females
- Breeds with increased incidence include English Springer Spaniels and Shetland Sheepdogs
Causes of Skin Cancer (Squamous Cell Carcinoma) in Dogs
It can be difficult to pinpoint the exact cause of cancer since many genetic and environmental factors probably play a part. These are some of the conditions which may put your dog at an increased risk of developing squamous cell carcinoma.
- Age – the mean age for diagnosis of squamous cell carcinoma is between 6 and 11 years old; risk generally increases with age
- Exposure to sunlight – this is less obvious than it is with humans, but outdoor dogs are more at risk
- Short haired dogs
- Dog with dark colored coats
- Large breed dogs
- Papilloma virus
Diagnosis of Skin Cancer (Squamous Cell Carcinoma) in Dogs
Squamous cell carcinoma resembles many other skin tumors, so the veterinarian will need to examine a sample of the tumor with cytology to make an accurate diagnosis. A biopsy or needle aspirant will be taken with a local anesthetic. In some cases, the veterinarian may decide to surgically remove the tumor first, and diagnose the cancer microscopically after removal.
Bloodwork will likely be taken to evaluate your dog’s immune system and check for signs of systemic illness from metastasis. Dogs with affected lymph nodes may show a low lymphocyte count on a blood test. X-rays may also be necessary to check for metastatic tumors in the lungs, especially with subungual squamous carcinoma.
Treatment of Skin Cancer (Squamous Cell Carcinoma) in Dogs
Surgical excision is the most effective treatment for squamous cell carcinoma. A 2cm margin around the tumor will be needed to ensure the removal of all cancerous tissue. With subungual tumors, this usually involves removing the entire digit. Since squamous cell carcinomas are skin tumors, most surgeries are minimally invasive. You will need to clean and check the area regularly after surgery, and try to keep your dog from scratching at the incision. A return check-up may be needed several weeks later.
There are a few alternative treatments if your dog is not healthy enough for surgery, or if the cancer is still in the very early stages. Intralesional implant chemotherapy is the insertion of a sustained release gel implant containing a chemotherapy medication such as fluorouracil or cisplatin. This treatment has had a reasonable success rate with squamous cell carcinoma in dogs. Etretinate, a medication that is sometimes used for very severe psoriasis, has also been effective at treating squamous cell lesions in the early stages. This is less effective on lesions that are very aggressive, and treatment may have to be carried out for up to ninety days.
Recovery of Skin Cancer (Squamous Cell Carcinoma) in Dogs
Squamous cell carcinoma treatment has a much higher success rate than other forms of cancer, as long as the tumor has not metastasized to other areas of the body. Studies have found that 95% of dogs that have surgery on a squamous cell carcinoma survive for at least one year after surgery. With repeat surgery on subungual tumors, 60% of dogs still survived for at least one year; however when internal metastasis was present, the survival rate at one year was only 10 %. Like most forms of cancer, a complete cure is rare, but this type of cancer is usually treatable as long as it is caught in the early stages.
Skin Cancer (Squamous Cell Carcinoma) Questions and Advice from Veterinary Professionals
Has Symptoms
L hind paw lesion- seen initially 2/1918 by a vet who said it was inflammatory after doing needle aspiration. Simplicef given- no change.
He is an 11 yr. old Alaskan husky. No overt symptoms other than lesion which I noticed. Took him to another vet this past week - another needle aspiration. Supposedly SCC. Vet recommends surgery. I am thinking entire toe should be amputated even though it is next to the toe. Would you recommend this? I am so disappointed that I didn't take him back sooner for a second opinion. No change in size of lesion. He acts as if it is not there. What is usual prognosis for this type of lesion post surgery? Thank you .
2514 Recommendations
Was this experience helpful?
Has Symptoms
My brother’s walker hound, Sully, has oral SCC in his upper palette & to ensure complete removal much of his upper jaw & nose must be removed. A spot has been detected on one lung but hasn’t increased in size over 2 weeks so metastasis is unknown. The oncologist feels surgery is still the best option but can a hound who lives nose to the ground have sufficient quality after such surgery?
2514 Recommendations
Add a comment to Sully's experience
Was this experience helpful?
Has Symptoms
My dog was recently diagnosed with stage IV SCC. My vet said that there is nothing that we can do by this point, as she is 12 years old and likely would not make it through surgery. My dog's tumor has grown about 4x as big in the last month. M vet says that I will likely have to put her down in the next 2-4 weeks. I was just wondering if you could give me a second opinion on her life expectancy and if there is really nothing else I can do. I just love her so much, I'm not ready to say goodbye. :(
1101 Recommendations
My 12 year Jack Russell dog (Dotty) was diagnosed at the beginning of January with oral SCC. After going to an oncology specialist, he advised that they could not operate due to the size. After speaking with our vets too, there is nothing more that can be done except keep her comfortable. It’s heartbreaking to be told a few weeks to a small number one f months. I hope you’re enjoying your remaining time with Daisy, I understand and going through the same.
Add a comment to Daisy's experience
Was this experience helpful?
Has Symptoms
My dog Lily, a pit/beagle/boxer mix will be 8 this year, and in the last month, I noticed on her left side, by her ribs, a small bump. It felt like a scab from a possible tick bite I didnt notice. But now its about a pea/pea and a half pea sized. It's under her (thin) coat, so I cant see it that well, but it feels rough on the outside, while my dog is not showing paid when I touch it. She has had issues with skin and coat allergies, as she will get a loss of coat in the spring, and late fall/early winter so I'm not sure if this is a allergy thing I could self treat or if Im looking at something cancerous that I should bring her to our vet to get aspirated.
1101 Recommendations
Add a comment to Lily's experience
Was this experience helpful?
Has Symptoms
Medication Used
My dog has a sore in his right nostril. My vet said he thinks it's an scc. He is blind and quite an old 11 year old entire male golden retriever so I don't feel cutting it out or radiation treatment is an option. He gets severe seperation anxiety if he is not with me. I would like to know what the process is as I don't want him to suffer and I want to be prepared. How long does he have without treatment? How long after finding it would it effect his quality of life? Currently he snores and sometimes has to catch his breath. He sneezes quite a bit in the morning when he wakes up. Sometimes it bleeds so I've been keeping his nose moist with paw paw ointment. His eyes have started watering a bit in the last 2 days. And now I think his muzzle is a bit swollen
2514 Recommendations
There is a wide window for life expectancy and progression of the condition and if there is bleeding the time is generally shorter; mean survival time is around three months but depending on various variables this time may be measured in a few weeks to eight months. Quality of life again depends on current severity and is again variable. Your Veterinarian would be able to guide you better regarding Odin’s specific case and there are exceptions which may live longer but are rare. Regards Dr Callum Turner DVM
www.ncbi.nlm.nih.gov/pubmed/8680915
Add a comment to Odin's experience
Was this experience helpful?
Has Symptoms
my all white female pitbull is 12 years old. About a year ago the vet discovered she has skin cancer (squamous cell carcinoma).. was about golf ball size till i got it surgically removed. As soon as it healed, it grew back. Now its a little bigger than a golf ball size. And i dont know what to do. I dont want her to suffer.. but i dont want her to go through getting the tumor surgically removed again & it grow back once again.
i have been giving her pain meds & amoxicillin.
2514 Recommendations
Squamous cell carcinomas are locally invasive but are slow to spread to other areas of the body. Surgical excision with wide margins is the treatment of choice, sometimes depending on the location (the head) wide margins are not possible; however the recurrence rate is high and other treatments like radiotherapy may be required after surgery, your Veterinarian would be able to discuss these options with you. A sample should be taken for histopathology to determine the likelihood of metastasis which would help determine a treatment plan. Regards Dr Callum Turner DVM
It certainly wasn't slow to metastasis with my girl. Digital SCC April....toe amputated....Day before Thanksgiving, biopsy results from enlarged right prescapular lymph node, indicate return. Following Monday, a single, 1 cm metastasis on lung was found. She is receiving 4 palliative radiation treatments, as well as taking Palladia (130 mg on Monday, Wed & Fri), Piroxicam (14 mg on Tue, Thur, Sat, Sun), in conjunction with Omeprazole and Cerenia to help protect her GI from the Palladia. Anything aside from this you would consider if she was your patient? As long as her doctor doesn't forbid additional, non-traditional medicines (or perhaps you think a drug other than Palladia might be more promising), I consider it my responsibility to throw everything except the kitchen sink at this nasty disease.....for as long as her quality of life warrants the fight. If I simply agree to wait and see how long she survives on this treatment, she will be gone far sooner than she really should be. I am heart broken.
Add a comment to wera's experience
Was this experience helpful?
Add a comment to Howie's experience