Titration of Dietary Iodine for Maintaining Normal Serum Thyroxine Concentrations in Hyperthyroid Cats

Melendez L.D., Yamka R.M. and Burris P.A.

Conference Proceedings, (2011). American College of Veterinary Internal Medicine:

We have shown previously that restriction of dietary iodine (I) is a safe and effective method for decreasing serum thyroxine concentrations (TT4) in cats with hyperthyroidism. The objective of this study was to determine the maximum level of iodine in a nutritionally balanced feline mature adult food required to maintain normal serum TT4 concentrations in hyperthyroid cats currently being controlled on a food containing 0.15 ppm I (DMB) as measured by epiboron neutron atomic activation. All cats were previously diagnosed at least 14 months prior to the start of the study and their TT4 concentrations were maintained in the normal range by dietary iodine restriction for a minimum of 10 months (range 10 months- 3 years). Serum TT4 concentrations ranged from 9–42 nmol/l (reference range 10–55 nmol/l) at the beginning of the study.