OBJECTIVE: To assess perioperative findings and postoperative complications and outcomes in dogs that had ectopic thyroid carcinomas with invasion into the hyoid apparatus and underwent tumor excision with partial hyoidectomy. DESIGN: Retrospective case series. ANIMALS: 5 client-owned dogs. PROCEDURES: Medical records of dogs that had an ectopic neuroendocrine tumor with invasion into the hyoid apparatus and underwent tumor excision with partial hyoidectomy were reviewed for information regarding perioperative and postoperative findings and outcome. During surgery in each case, the thyrohyoid and ceratohyoid or epihyoid bones (depending on degree of hyoid apparatus involvement) were sharply transected, allowing en bloc removal of the tumor. The ipsilateral cut ends of the thyrohyoid and ceratohyoid or epihyoid bones (depending on which was cut) were sutured together with polypropylene suture in a simple interrupted pattern. RESULTS: All partial hyoidectomy procedures were completed without surgical or anesthetic complications. All 5 dogs were able to eat and drink between 7 and 24 hours after surgery, with no signs of dysphagia, ptyalism, or abnormal tongue carriage. Follow-up information was obtained over a period of 173 to 587 days after surgery for all 5 dogs; 4 dogs were still alive at last follow-up. One dog was euthanized 587 days after surgery because of lethargy, inappetence, and hypercalcemia. CONCLUSIONS AND CLINICAL RELEVANCE: From this limited series of cases, results suggested that partial resection of the hyoid apparatus during removal of ectopic thyroid carcinoma may be tolerated well and be associated with very good functional outcomes in dogs.