| 英文描述 | Rare. Excessive secretion of thyroid hormone is due to tumors of the thyroid gland; adenocarcinomas predominating over adenomas. Ectopic thyroid carcinomas have been reported. Metastases often occur from adenocarcinomas, and metastases have been found at the time of initial diagnosis in over 1/3 of dogs with thyroid carcinomas. Dx is based on history, clinical signs, biopsy, and scintigrams of the thyroid. T3 and T4 levels are usually increased, but bilateral tumors can cause lower-than-normal levels with hypothyroidism and many dogs with thyroid tumors are euthyroid. |
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