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Pet Health Articles

Cancer & Tumors

  • Neuroendocrine tumors are a group of tumors that develop from the cells of the neuroendocrine system, and include insulinomas, gastrinomas, glucagonomas, carcinoids, medullary thyroid carcinomas, small-cell lung carcinomas, pheochromocytomas, chemodectomas, and Merkel cell carcinomas. Some of these tumors are functional, while others are non-functional. The signs of disease in dogs and cats depend on the type of growth, location of the tumor, its size, the degree of infiltration in the surrounding tissues, whether it has metastasized, and whether it is functional. A definitive diagnosis requires tissue biopsy and histopathology, often with histochemical staining and electron microscopy. Staging is highly recommended for these tumors. Treatment may involve surgery, chemotherapy, radiation therapy, and medical and dietary management.

  • Odontogenic fibromas, sometimes previously referred to as an epulis, are benign tumors of the mouth often at the front of the upper jaw. These may be locally invasive and may cause some oral pain. Surgery is the recommended course of action to treat this condition.

  • Oral squamous cell carcinomas (SCC) are the most common oral tumor in cats, and second most common in dogs. These tumors are locally aggressive, with a possibility to metastasize. Regardless of the location of SCC, surgery is the typically the standard treatment. Radiation therapy may be recommended following surgery or as a primary treatment for palliative care. Staging is recommended for all cases. If metastasis is present chemotherapy is often pursued.

  • Fibrosarcomas are the second most common oral tumor in cats and arise from the fibrous and connective tissues of the oral cavity. These tumors are very invasive locally and are often difficult to manage, Diagnosis is based on biopsy and treatment involves surgery and occasionally radiation or chemotherapy. Palliative care with pain relief and antibiotics are essential to improve quality of life.

  • The most common oral tumor seen in cats is squamous cell carcinoma; the second most common is fibrosarcoma. This handout discusses the clinical signs, diagnosis and treatment of oral tumors in cats.

  • Fibrosarcomas are the third most common oral tumor in dogs and arise from the fibrous and connective tissues of the oral cavity. These tumors are very invasive locally and are often difficult to manage, Diagnosis is based on biopsy. Treatment involving surgery and radiation provide the longest survival times.

  • Oral melanomas are the most common malignant oral tumor in dogs. Melanomas usually present as a mass in the mouth and may be melanotic (pigmented) or amelanotic (non-pigmented). These tumors are both locally invasive and have a high tendency to metastasize to other organs. Full staging including CT scanning is recommended to determine the extent of the disease.

  • Like humans, benign and malignant tumors occur in dogs’ mouths. Peripheral odontogenic fibromas (POF) are the most common benign tumors while oral melanomas, squamous cell carcinomas, and fibrosarcomas are the most prevalent malignant tumors in dogs. Diagnosis may be performed via fine needle aspiration or biopsy. Spread to mandibular lymph nodes does occur. Fine needle aspiration of the lymph nodes is recommended when malignant tumors are suspected. Tumor staging including laboratory testing as well as CT imaging helps to plan therapy.

  • This handout discusses some of the more common forms of oral tumors in pets. Highlighted are Papillomas (“Warts”) and Fibropapillomas, both of wish are caused by viral infection. Clinical signs, diagnostic methods, and treatment options are highlighted.

  • Osteosarcomas are somewhat rare in cats and progress slowly. Osteosarcoma is very painful. The most common location where osteosarcomas develop in cats is the hindlimb. Amputation is by far the most common treatment. Chemotherapy is not generally pursued without evidence of metastasis, given the relatively long-term control with surgery alone.