title: Equine thyroid dysfunction.
abstract: 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.
authors.affiliation: Department of Large Animal Clinical Sciences, College of Veterinary Medicine, University of Tennessee, Knoxville, TN 37996-4545, USA. nfrank@utk.edu
authors.forename: Nicholas
authors.initials: N
authors.lastname: Frank
authors.forename: Janice
authors.initials: J
authors.lastname: Sojka
authors.forename: Nat T
authors.initials: NT
authors.lastname: Messer
mesh_terms: 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
chemical_list: D014284:Triiodothyronine