title: Administration of levothyroxine to euthyroid dogs does not affect echocardiographic and electrocardiographic measurements.
abstract: The effects of a replacement dose of levothyroxine on electrocardiographic and echocardiographic parameters in euthyroid dogs were examined. Two-dimensional guided M-mode echocardiograms and electrocardiograms were obtained before and after administration of levothyroxine (0.5 mg m-2 twice a day) to 10 euthyroid dogs for a period of eight weeks; four untreated dogs acted as controls. The resting serum total thyroxine concentration was significantly increased in treated dogs during weeks 4 to 8. There were no significant differences in any of the echocardiographic or electrocardiographic measurements resulting from treatment.
authors.affiliation: Department of Medical Sciences, School of Veterinary Medicine, University of Wisconsin-Madison.
authors.forename: D L
authors.initials: DL
authors.lastname: Panciera
authors.forename: B W
authors.initials: BW
authors.lastname: Keene
authors.forename: H C
authors.initials: HC
authors.lastname: Mier
mesh_terms: D000818:Animals; D004283:Dog Diseases / Q000139:chemically induced / Q000188:drug therapy* / Q000503:physiopathology; D004285:Dogs; D004452:Echocardiography / Q000187:drug effects / Q000662:veterinary*; D004562:Electrocardiography / Q000187:drug effects / Q000662:veterinary*; D005260:Female; D006980:Hyperthyroidism / Q000139:chemically induced / Q000503:physiopathology; D007037:Hypothyroidism / Q000188:drug therapy / Q000662:veterinary*; D008297:Male; D013974:Thyroxine / Q000009:adverse effects* / Q000627:therapeutic use
chemical_list: D013974:Thyroxine