By VIN Community Contributors
Becky Lundgren, DVM
Courtney before surgery. All the visible teeth in this photo define the area that was later removed; her lower jaw was amputated straight across behind the lower canine teeth. Photo courtesy of David Jensen of Alaska Pet-ography.
When squamous cell carcinoma occurs in the mouth and throat, it’s called oral squamous cell carcinoma. In these oral cases, the lesion is usually located on the gums or tonsils. In cats, SCC is the most common oral cancer. In dogs, SCC is one of the three most common tumors in that area.
Signs can include drooling (with or without blood), difficulty eating, and halitosis (very bad breath). Depending on the tumor’s location, the pet can have trouble swallowing, or may cough. If the mouth is too uncomfortable for the pet to eat normally, the animal will lose weight. As is true with many cancers, affected dogs and cats tend to be older animals.
Diagnostics include radiographs of the local site, radiographs of the lungs to see if there has been metastasis (spread to other locations), and tumor sample collection (biopsy). Sometimes a fine needle aspirate (FNA) will provide enough sample tissue for diagnosis.
Treatment may involve surgery, radiation therapy, and/or chemotherapy. Treatment depends on location, amount of tissue involved, etc.
Courtney two years after surgery. Although the jaw is foreshortened, excess skin was shaped in surgery to help improve function and also extend the appearance of the lower jaw. Photo by Peg Banks.
If the tumor hasn’t metastasized, surgery is the preferred treatment. The entire tumor, including the extensions into underlying tissue and bone, will be removed. Often, part of the jawbone has to be removed. Surgery can provide a cure if the pet has clean margins (the tumor was completely removed). Dogs do quite well with partial jaws. Surprisingly enough, it doesn’t typically alter the dog’s appearance as much as you might expect. Even if surgery isn’t curative, surgery can extend survival.
Radiation therapy can be used if surgery isn’t an option, or if surgery can’t completely remove the tumor.
Chemotherapy may be added to therapy, depending on the circumstances.
Prognosis for oral squamous cell carcinoma depends on the location of the tumor and if it has spread. Typically, if surgery does not result in clean margins, treatment is aimed at prolonging quality of life. A complete cure is unlikely unless diagnosis is made early. If the tumor is not in the tonsils and hasn’t spread, the prognosis is good with surgery and/or radiation treatment. Tumors that are located in the tonsils tend to be quite aggressive and have a poor prognosis.