title: Effects of trimethoprim-sulfadiazine on thyroid function of horses.
abstract: Trimethoprim-sulfadiazine was administered to horses in a randomized, placebo controlled study to determine the effects of potentiated sulfonamides on thyroid function in normal horses. The treatment group included eight horses that received trimethoprim-sulfadiazine mixed with molasses orally at 30 mg/kg once daily for eight weeks. The control group included 8 horses that received an oral placebo (flour mixed with molasses) once daily for the same period. Thyroid function was evaluated prior to initiation of treatment and after 8 weeks of treatment. Serum concentrations of total and free triiodothyronine (T3), total and free thyroxine (T4), and thyroid stimulating hormone (TSH) were determined at rest and after a thyrotropin-releasing hormone (TRH) stimulation test. There was no detectable difference between treatment and control groups.
authors.affiliation: Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Washington State University, Pullman, WA 99164-7060, USA.
authors.forename: Chantal M
authors.initials: CM
authors.lastname: Rothschild
authors.forename: Melissa T
authors.initials: MT
authors.lastname: Hines
authors.forename: Babetta
authors.initials: B
authors.lastname: Breuhaus
authors.forename: John
authors.initials: J
authors.lastname: Gay
authors.forename: Debra C
authors.initials: DC
authors.lastname: Sellon
mesh_terms: D000284:Administration, Oral; D000818:Animals; D000890:Anti-Infective Agents / Q000008:administration & dosage / Q000097:blood / Q000494:pharmacology*; D004359:Drug Therapy, Combination; D005260:Female; D006736:Horses / Q000378:metabolism*; D008297:Male; D013411:Sulfadiazine / Q000008:administration & dosage / Q000097:blood / Q000494:pharmacology*; D013960:Thyroid Function Tests / Q000662:veterinary; D013961:Thyroid Gland / Q000187:drug effects*; D013963:Thyroid Hormones / Q000097:blood; D014295:Trimethoprim / Q000008:administration & dosage / Q000097:blood / Q000494:pharmacology*
chemical_list: D000890:Anti-Infective Agents; D013963:Thyroid Hormones; D013411:Sulfadiazine; D014295:Trimethoprim