Equine thyroid dysfunction.
Hypothyroidism is the most common type of thyroid gland dysfunction reported in horses. Primary, secondary, and tertiary causes of hypothyroidism are discussed. Equine hypothyroidism remains a controversial endocrine disorder because extrathyroidal factors, including the administration of drugs and systemic diseases, affect serum triiodothyronine (T3) and thyroxine (T3) concentrations in horses. Accurate diagnosis of hypothyroidism therefore requires assessment of the hypothalamic-pituitary-thyroid axis. Diagnostic procedures for evaluating thyroid gland function are outlined and results of studies utilizing experimental models are discussed.
Frank
Nicholas
N
Department of Large Animal Clinical Sciences, College of Veterinary Medicine, University of Tennessee, Knoxville, TN 37996-4545, USA. nfrank@utk.edu
Sojka
Janice
J
Messer
Nat T
NT
D000818:Animals; D004195:Disease Models, Animal; D006734:Horse Diseases / Q000175:diagnosis* / Q000209:etiology; D006736:Horses; D007037:Hypothyroidism / Q000175:diagnosis / Q000209:etiology / Q000662:veterinary*; D013959:Thyroid Diseases / Q000175:diagnosis / Q000209:etiology / Q000662:veterinary*; D013960:Thyroid Function Tests / Q000662:veterinary*; D014284:Triiodothyronine / Q000097:blood
D014284:Triiodothyronine