A Case of Thyroid Cancer in a Captive Raccoon ( <i>Procyon lotor</i>)

We report a cervical mass that was observed in a captive raccoon (Procyon lotor).On the 71st day, surgical removal was performed.Histopathological examination diagnosed the mass as thyroid adenocarcinoma.Following tumor removal, the animal remained in good condition but died on the 230th postoperative day.Postmortem histopathological examination revealed no metastasis of the thyroid adenocarcinoma; however, verrucous endocarditis was identified, and the cause of death was determined to be heart failure.This is the first report in Japan describing the clinical course of thyroid cancer in a raccoon.