Topography
Each lobe lies on the dorsolateral surface of the trachea, at about tracheal rings 1 to 8, medial to the common carotid artery. In the dog the isthmus joining the lobes is usually absent or thin, except in some large breeds. The external and internal parathyroid glands sit at the cranial pole of each lobe.
Clinical relevance
- Hypothyroidism: a common endocrinopathy of adult dogs (lymphocytic thyroiditis or idiopathic atrophy); causes lethargy, weight gain and symmetrical alopecia.
- Thyroid carcinoma: a palpable cervical mass; in the dog most thyroid tumours are malignant.
- Thyroidectomy: the parathyroids must be preserved to avoid hypocalcaemia.
3D model
Schematic shape (illustrative fidelity), placed from landmarks on the skeleton and the scanned organs. It shows topography, not fine morphology.