title: Use of thyroid scintigraphy and pituitary immunohistochemistry in the diagnosis of spontaneous hypothyroidism in a mature cat.
abstract: A 12-year old, castrated male domestic shorthair cat presented with a 2-year history of poor hair coat, seborrhea, generalized pruritus and otitis externa. Low circulating concentrations of total serum thyroxine (TT(4)) and free thyroxine (fT(4)) and an elevated thyroid stimulating hormone concentration supported a diagnosis of primary hypothyroidism. Thyroid scintigraphy did not show uptake of radioactive technetium in the thyroid area. Treatment with levothyroxine resulted in clinical improvement. Recurrence of dermatitis 8 months after onset of treatment resulted in euthanasia of the cat. On post-mortem examination, thyroid tissue was not identified on gross or histological examination. Pituitary immunohistochemistry identified hyperplasia of chromophobe cells.
authors.affiliation: Department of Clinical Studies, Ontario Veterinary College, University of Guelph, Guelph, Ontario, Canada. sblois@uoguelph.ca
authors.forename: Shauna L
authors.initials: SL
authors.lastname: Blois
authors.forename: Anthony C G
authors.initials: AC
authors.lastname: Abrams-Ogg
authors.forename: Colleen
authors.initials: C
authors.lastname: Mitchell
authors.forename: Anthony
authors.initials: A
authors.lastname: Yu
authors.forename: Debbie
authors.initials: D
authors.lastname: Stoewen
authors.forename: Brandon N
authors.initials: BN
authors.lastname: Lillie
authors.forename: Matti
authors.initials: M
authors.lastname: Kiupel
mesh_terms: D000818:Animals; D002371:Cat Diseases / Q000097:blood / Q000000981:diagnostic imaging*; D002415:Cats; D003937:Diagnosis, Differential; D017809:Fatal Outcome; D007037:Hypothyroidism / Q000097:blood / Q000000981:diagnostic imaging / Q000662:veterinary*; D007150:Immunohistochemistry / Q000662:veterinary; D008297:Male; D010902:Pituitary Gland / Q000473:pathology*; D011877:Radionuclide Imaging; D013961:Thyroid Gland / Q000000981:diagnostic imaging*; D013972:Thyrotropin / Q000097:blood; D013974:Thyroxine / Q000097:blood
chemical_list: D013972:Thyrotropin; D013974:Thyroxine
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