Hypofractionated radiation therapy of a thyroid tumor in a pet raccoon (Procyon lotor).

Thyroid neoplasia has been documented in raccoons; however, successful management and treatment has not been well-described. A 15-year-old, intact female pet raccoon (Procyon lotor) was examined for evaluation of a right-sided ventral cervical mass and a cough of 4 to 5 mo duration. Cytology and computed tomography (CT) findings of the mass were most consistent with a thyroid tumor. The raccoon was treated with a hypofractionated external beam radiation protocol (8 Gy/fraction for 4 once/wk fractions). Treatments were well-tolerated and no radiation-induced side effects were detected. This is the first report of radiation treatment of thyroid neoplasia in a raccoon, presenting the challenges of animals that are difficult to handle or medicate. Copyright and/or publishing rights held by the Canadian Veterinary Medical Association.