The thyroid gland is an integral part of the complex anatomy of the horse's neck. Transcutaneous ultrasonography provides a non-invasive method for assessing the thyroid gland's parenchyma and dimensions in horses. This study evaluated 30 clinically healthy Turkmen horses, with health status confirmed through comprehensive physical examination, complete blood count, serum biochemical profiling, and thyroid hormone analysis. The horses were divided into two age groups: Group 1 under 36 months (3 males, 8 females), and Group 2: 36 months and older (8 males, 11 females).
Ultrasonographic assessment of the thyroid region was performed using a high-frequency linear probe. Each thyroid lobe was systematically evaluated for its dimensions, volume, morphological appearance, contour, parenchymal echogenicity and echotexture.
Statistical analysis revealed no significant age-related differences (p > 0.05) in thyroid parameters; however, sex-based differences were observed: females had significantly greater length and volume in both left and right thyroid lobes compared to males (p < 0.05).
Qualitative B-mode ultrasonography showed consistent morphological features; longitudinal view, all thyroid lobes exhibited a flat, oval shape. Transversely, most lobes (83.93%, n=47) were elliptical appearance, while the reminder lobes (16.07%, n=9) were spherical. Irrespective of the shape, all thyroid lobes demonstrated regular contour margins. Echogenicity: most lobes were hyper-echoic, with a few being iso-echoic, when compared to the sternocephalic muscle. Furthermore, regarding echotexture, all thyroid lobes were evaluated as mildly to moderately heterogeneous.
This study establishes diagnostic baselines for thyroid evaluation in Turkmen horses breed aiding in the detection and management of thyroid pathologies.