Parathyroidectomy

After the diagnosis of primary hyperparathyroidism with elevated ionized calcium, normal to high level of parathyroid hormones (PTH) and PTH related protein being undetectable, the abnormal parathyroid gland needs to be removed. Usually primary hyperparathyroidism is due to an adenoma from one of the four parathyroid glands normally present in dogs and cats. Keeshounds may have several nodules present.

There are two external and two internal parathyroid glands in dogs and cats. They are located, respectively, at the cranial pole of the thyroid gland and within the parenchyma of the thyroid gland toward the caudal pole. Parathyroid nodules are well visualized on ultrasounds. Absence of a nodule on ultrasounds does not rule out the diagnosis of primary hyperthyroidism.

Parathyroid gland can be ablated with ethanol injection or heat under ultrasound guidance. This technique does not allow tissue collection for histology and requires several injection to completely eliminate the abnormal parathyroid gland. Surgical resection of the nodule is the technique of choice for the treatment of primary hyperparathyoridism. It provides tissue sample for histological diagnosis and it allows a complete evaluation of the other parathyroid glands. The recurrence rate at the ablation site is as high as 7%.  [...]