title: Effect of Feeding an Iodine-Restricted Diet in Cats with Spontaneous Hyperthyroidism.
abstract: BACKGROUND
  Exclusive feeding of an iodine-restricted diet has been proposed as a method for controlling clinical manifestations of hyperthyroidism in hyperthyroid cats.
  
  
  OBJECTIVE
  To determine the effect of feeding an iodine-restricted diet on TT4 concentrations and clinical signs in cats with spontaneous hyperthyroidism.
  
  
  METHODS
  Forty-nine client-owned cats with spontaneous hyperthyroidism.
  
  
  METHODS
  Retrospective case series. Hyperthyroid cats were exclusively fed a commercially available iodine-restricted diet. Clinical response was assessed by change in weight and heart rate and serum TT4, blood urea nitrogen (BUN), and creatinine concentrations at various times during dietary management (21-60 days, 60-180 days).
  
  
  RESULTS
  Serum TT4 normalized in 20/48 cats (42%) and 39/47 cats (83%) at 21-60 days and 61-180 days, respectively. Cats in which the TT4 concentrations were still above reference range at 21-60 days had a significantly higher starting TT4 than those that normalized their TT4 levels during the same time period (P = .038). Body weight did not significantly increase (P = .34) nor heart rate decrease (P = .64) during the study. There was a significant decrease in serum creatinine (P = .028). Cats in the low reference range for serum TT4 concentrations did not have a significant increase in body weight (P = .41) nor creatinine (P = .54) when compared to those with high reference range.
  
  
  CONCLUSIONS
  Restricted-iodine diets were effective at maintaining serum TT4 concentrations within reference ranges for a majority of cats with spontaneous hyperthyroidism over 1 year, although not all clinical signs of hyperthyroidism improved.
authors.affiliation: Department of Veterinary Clinical Sciences, Purdue University College of Veterinary Medicine, West Lafayette, IN.
authors.forename: T Y
authors.initials: TY
authors.lastname: Hui
authors.affiliation: VCA-West Los Angeles Animal Hospital, Los Angeles, CA.
authors.forename: D S
authors.initials: DS
authors.lastname: Bruyette
authors.affiliation: Department of Veterinary Clinical Sciences, Purdue University College of Veterinary Medicine, West Lafayette, IN.
authors.forename: G E
authors.initials: GE
authors.lastname: Moore
authors.affiliation: Department of Veterinary Clinical Sciences, Purdue University College of Veterinary Medicine, West Lafayette, IN.
authors.forename: J C
authors.initials: JC
authors.lastname: Scott-Moncrieff
mesh_terms: D000821:Animal Feed; D000818:Animals; D002371:Cat Diseases / Q000178:diet therapy*; D002415:Cats; D004032:Diet / Q000662:veterinary; D005260:Female; D006980:Hyperthyroidism / Q000178:diet therapy / Q000662:veterinary*; D007455:Iodine / Q000008:administration & dosage*; D008297:Male; D012189:Retrospective Studies; D013974:Thyroxine / Q000097:blood; D016896:Treatment Outcome
chemical_list: D007455:Iodine; D013974:Thyroxine
keywords: Endocrine; Feline; Thyroid gland; Thyroid hormone