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 tumours in that area.


Signs can include drooling (with or without blood), difficulty eating, and halitosis (very bad breath). Depending on the tumour’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.

Diagnostic Tests

Diagnostics include radiographs of the local site, radiographs of the lungs to see if there has been metastasis (spread to other locations), and tumour 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.

If the tumour hasn’t metastasized, surgery is the preferred treatment. The entire tumour, 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 tumour 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 tumour.

Chemotherapy may be added to therapy, depending on the circumstances.


Prognosis for oral squamous cell carcinoma depends on the location of the tumour 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 tumour is not in the tonsils and hasn’t spread, the prognosis is good with surgery and/or radiation treatment. Tumours that are located in the tonsils tend to be quite aggressive and have a poor prognosis.