Serial determination of thyroxine concentrations in hyperthyroid cats.

M. R. Broome, Edward C Feldman, J. M. Turrel

Research output: Contribution to journalArticlepeer-review

23 Scopus citations


Serum thyroxine (T4) concentrations of 10 hyperthyroid cats were measured at hourly intervals between 9 AM and 4 PM. In 5 cats, blood samples were obtained by jugular venipuncture; the remaining 5 cats had blood samples obtained from jugular catheters. Over the 7-hour period, a significant temporal (diurnal) variation was not identified in the serum T4 concentrations of the cats (P greater than 0.01). The lowest mean serum T4 concentration (9.1 micrograms/dl) was measured at 3 PM and was 14.2% less than the highest mean serum T4 concentration (10.6 micrograms/dl) measured at 9 AM. Though there were fluctuations in serum T4 concentrations during the 7-hour period, the differences were not systematic. The maximal variation in serum T4 concentrations over the 7-hour period averaged less than 21%. Despite the random variations during the 7-hour period, none of the measured serum T4 concentrations was in the normal range. Measurement of serum T4 concentration from randomly obtained blood samples was determined to be reliable for diagnosing feline hyperthyroidism.

Original languageEnglish (US)
Pages (from-to)49-51
Number of pages3
JournalJournal of the American Veterinary Medical Association
Issue number1
StatePublished - Jan 1 1988

ASJC Scopus subject areas

  • veterinary(all)


Dive into the research topics of 'Serial determination of thyroxine concentrations in hyperthyroid cats.'. Together they form a unique fingerprint.

Cite this