Dog Parvo Symptoms

Periorbital and facial tumors:

Many types of tumors may occur in this area. Examples may include Lymphoma, Osteosarcoma, Mast cell tumor, Reticulum cell sarcoma, Fibrosarcoma, optic nerve Meningioma, Neurofribrosarcoma, Glial,Carcinomas, Undifferentiatedtumors, and others

Periorbital tumors may originate from either the surrounding soft tissues, or bone, or may result from extension of other primary tumors originating in the nasal cavity, maxilla or optic nerve. Many of these tumors cannot be completely resected surgically with good margins because of location and surrounding critical tissues. Response to radiation greatly depends on the type and grade of tumor. Many periorbital tumors are successfully treated with radiation therapy, with or without adjuvant therapy.

Auricular and periauricular tumors:

Theoretically, any cutaneous or soft tissue tumors can occur in the periauricular area. It is not uncommon to find Mast cell tumors, Fibrosarcomas and other Soft tissue sarcomas. As with treating these tumors in other areas of the body, radiation therapy has been successful, although the success rate depends on the grade and type of tumor.

Ceruminous gland adenocarcinoma (CGA) is the most common tumor of the ear canal found in both dogs and cats. In one study, aggressive surgery (ablation of the ear canal and bulla osteotomy) resulted to a median disease-free interval of 42 months. Another study using radiation alone, or in combination with surgery, resulted in a tumor-free survival time of 39 months. In cats, when the tumor invades outside the ear, surgery alone is unlikely to result to a long-term remission and radiation is usually required as an adjuvant treatment for better tumor control.

Squamous cell carcinoma of the ear canal and bulla tend to be more invasive, have a higher metastatic potential, and often compromise the adjacent brain tissue. Thus, the prognosis is significantly poorer than CGA, and these tumors should be thoroughly staged before the type of treatment is considered.

Pharyngeal, laryngeal, thyroid and other:

Common malignant tumors occurring in these areas include: Osteosarcoma, Chondrasarcoma, Undifferentiated carcinoma, Fibrosarcoma, Mast cell, Adenocarcinoma, Squamous cell carcinoma, Plasmacytoma and Lymphoma. Limited data is available on malignant tumors in these regions since few have been reported, but most do tend to be very invasive with significant metastatic behavior. Depending on the tumor type and its expected radiosensitivity (based on treatments at other sites), radiation may help control the tumor while preserving laryngeal function.

Radiation is expected to offer good control of Lymphoma and Plasmacytoma of laryngeal and/or tracheal involvement.

Oncocytoma (also called rhabdomyoma) is a rare benign tumor involving the larynx and usually occurs in the younger mature dog. These tumors are usually successfully resected surgically, have a good prognosis, and are potentially curable. No data is presently available regarding radiation therapy of non-resectable oncocytomas.

Malignant thyroid carcinomas are unfortunately not as responsive to radiation therapy as are benign adenomas. I¹³¹treatment for malignant tumors has been attempted but does not result to the same satisfying success rate achieved in the hyperthyroid cats with benign tumors. Malignant thyroid tumors are best approached with a combination of surgery followed by external beam radiation or I¹³¹radiation treatment and chemotherapy. Although radiation therapy has been attempted on this type of tumor, data is limited due to the small number of reports.