title: Validation of an immunoassay for canine thyroid-stimulating hormone and changes in serum concentration following induction of hypothyroidism in dogs.
abstract: OBJECTIVE
  To validate a new immunoradiometric assay for canine thyroid-stimulating hormone (cTSH) and to document changes in serum cTSH concentration during induction of hypothyroidism in dogs.
  
  
  METHODS
  Six healthy adult male Beagles.
  
  
  METHODS
  Sensitivity, specificity, precision, and accuracy of the cTSH assay were evaluated in vitro. Hypothyroidism was induced in dogs by i.v. administration of sodium iodide I 131 solution. Subsequently, L-thyroxine was administered orally to normalize serum thyroxine concentrations.
  
  
  RESULTS
  The cTSH assay appeared to be specific and was sufficiently sensitive to detect cTSH in the serum of these dogs prior to induction of hypothyroidism. There was a 35-fold increase in mean serum cTSH concentration following induction of hypothyroidism, and 35 days after initiation of thyroid replacement therapy, mean serum cTSH concentration was not significantly greater than mean baseline value.
  
  
  CONCLUSIONS
  Assay of serum cTSH is likely to prove helpful in the differential diagnosis of primary, secondary, and tertiary hypothyroidism in dogs, and in monitoring response to thyroid hormone replacement treatment.
authors.affiliation: Department of Veterinary Clinical Sciences, School of Veterinary Medicine, Purdue University, West Lafayette, IN 47907-1248, USA.
authors.forename: D A
authors.initials: DA
authors.lastname: Williams
authors.forename: C
authors.initials: C
authors.lastname: Scott-Moncrieff
authors.forename: J
authors.initials: J
authors.lastname: Bruner
authors.forename: D
authors.initials: D
authors.lastname: Sustarsic
authors.forename: N
authors.initials: N
authors.lastname: Panosian-Sahakian
authors.forename: E
authors.initials: E
authors.lastname: Unver
authors.forename: A S
authors.initials: AS
authors.lastname: el Shami
mesh_terms: D000818:Animals; D003937:Diagnosis, Differential; D004283:Dog Diseases / Q000097:blood* / Q000175:diagnosis / Q000188:drug therapy; D004285:Dogs / Q000097:blood*; D007037:Hypothyroidism / Q000097:blood / Q000175:diagnosis / Q000188:drug therapy / Q000662:veterinary*; D008297:Male; D011863:Radioimmunoassay / Q000662:veterinary; D012016:Reference Values; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013972:Thyrotropin / Q000097:blood*; D013974:Thyroxine / Q000097:blood / Q000627:therapeutic use
chemical_list: D013972:Thyrotropin; D013974:Thyroxine