title: Effect of sulfadiazine and pyrimethamine on selected physiologic and performance parameters in athletically conditioned thoroughbred horses during an incremental exercise stress test.
abstract: Following the regimen used to treat equine protozoal myeloencephalitis, sulfadiazine (20 mg/kg) and pyrimethamine (1mg/kg) were administered orally once daily to 12 physically conditioned Thoroughbred horses for 4 consecutive days. The horses were randomly assigned to two test groups in a crossover design, with each horse serving as its own control. A stepwise exercise stress test was conducted to exhaustion. No effect on athletic performance was observed, and only marginal effects were noted in some hematologic and serochemical measurements, including decreased total white blood cell counts, red blood cell distribution width, total hemoglobin, serum sodium, and serum chloride. Serum folic acid concentration decreased significantly following sulfadiazine/pyrimethamine treatment.
authors.affiliation: Department of Large Animal Clinical Sciences, College of Veterinary Medicine, University of Florida, Gainesville 32610, USA.
authors.forename: Patrick T
authors.initials: PT
authors.lastname: Colahan
authors.forename: James E
authors.initials: JE
authors.lastname: Bailey
authors.forename: Martha
authors.initials: M
authors.lastname: Johnson
authors.forename: Brett L
authors.initials: BL
authors.lastname: Rice
authors.forename: Chi-Chung
authors.initials: CC
authors.lastname: Chou
authors.forename: Joseph P
authors.initials: JP
authors.lastname: Cheeks
authors.forename: Galin L
authors.initials: GL
authors.lastname: Jones
authors.forename: Mark
authors.initials: M
authors.lastname: Yang
mesh_terms: D000818:Animals; D000981:Antiprotozoal Agents / Q000097:blood / Q000493:pharmacokinetics / Q000494:pharmacology* / Q000652:urine; D001772:Blood Cell Count; D001786:Blood Glucose; D003404:Creatinine / Q000097:blood / Q000652:urine; D004359:Drug Therapy, Combination; D005080:Exercise Test / Q000187:drug effects / Q000662:veterinary; D005260:Female; D005492:Folic Acid / Q000097:blood; D006339:Heart Rate / Q000187:drug effects; D006736:Horses / Q000502:physiology*; D008297:Male; D010101:Oxygen Consumption / Q000187:drug effects; D010805:Physical Conditioning, Animal / Q000502:physiology*; D011739:Pyrimethamine / Q000097:blood / Q000493:pharmacokinetics / Q000494:pharmacology* / Q000652:urine; D013411:Sulfadiazine / Q000097:blood / Q000493:pharmacokinetics / Q000494:pharmacology* / Q000652:urine; D014805:Vitamin B 12 / Q000097:blood
chemical_list: D000981:Antiprotozoal Agents; D001786:Blood Glucose; D013411:Sulfadiazine; D005492:Folic Acid; D003404:Creatinine; D014805:Vitamin B 12; D011739:Pyrimethamine