title: Assessment of the value of quantitative thyroid scintigraphy for determination of thyroid function in dogs.
abstract: OBJECTIVE
  To assess the value of thyroid scintigraphy to determine thyroid status in dogs with hypothyroidism and various non-thyroidal illnesses.
  
  
  METHODS
  Thyroid hormone concentrations were measured and quantitative thyroid scintigraphy performed in 21 dogs with clinical and/or clinicopathological features consistent with hypothyroidism.
  
  
  RESULTS
  In 14 dogs with technetium thyroidal uptake values consistent with euthyroidism, further investigations supported non-thyroidal illness. In five dogs with technetium thyroidal uptake values within the hypothyroid range, primary hypothyroidism was confirmed as the only disease in four. The remaining dog had pituitary-dependent hyperadrenocorticism. Two dogs had technetium thyroidal uptake values in the non-diagnostic range. One dog had iodothyronine concentrations indicative of euthyroidism. In the other, a dog receiving glucocorticoid therapy, all iodothyronine concentrations were decreased. Markedly asymmetric technetium thyroidal uptake was present in two dogs. All iodothyronine concentrations were within reference interval but canine thyroid stimulating hormone concentration was elevated in one. Non-thyroidal illness was identified in both cases.
  
  
  CONCLUSIONS
  In dogs, technetium thyroidal uptake is a useful test to determine thyroid function. However, values may be non-diagnostic, asymmetric uptake can occur and excess glucocorticoids may variably suppress technetium thyroidal uptake and/or thyroid hormone concentrations. Further studies are necessary to evaluate quantitative thyroid scintigraphy as a gold standard method for determining canine thyroid function.
authors.affiliation: Veterinary Clinical Studies, School of Veterinary Medicine, University College Dublin, Belfield, Dublin 4, Ireland.
authors.forename: R E
authors.initials: RE
authors.lastname: Shiel
authors.forename: M
authors.initials: M
authors.lastname: Pinilla
authors.forename: H
authors.initials: H
authors.lastname: McAllister
authors.forename: C T
authors.initials: CT
authors.lastname: Mooney
mesh_terms: D000308:Adrenocortical Hyperfunction / Q000097:blood / Q000175:diagnosis / Q000000981:diagnostic imaging / Q000662:veterinary; D000818:Animals; D004283:Dog Diseases / Q000097:blood / Q000175:diagnosis / Q000000981:diagnostic imaging*; D004285:Dogs; D005260:Female; D007037:Hypothyroidism / Q000097:blood / Q000175:diagnosis / Q000000981:diagnostic imaging / Q000662:veterinary; D008297:Male; D011877:Radionuclide Imaging / Q000379:methods / Q000662:veterinary*; D013670:Sodium Pertechnetate Tc 99m; D013959:Thyroid Diseases / Q000097:blood / Q000175:diagnosis / Q000000981:diagnostic imaging*; D013960:Thyroid Function Tests / Q000379:methods / Q000662:veterinary*; D013961:Thyroid Gland / Q000000981:diagnostic imaging; D013963:Thyroid Hormones / Q000097:blood*
chemical_list: D013963:Thyroid Hormones; D013670:Sodium Pertechnetate Tc 99m