Serum free thyroxine levels in cats maintained on diets relatively high or low in iodine

Authors: Kyle AHM, Cooke RR, Tarttelin MF, Ford HC
Publication: New Zealand Veterinary Journal, Volume 42, Issue 3, pp 101-103, Jun 1994
Publisher: Taylor and Francis

Animal type: Cat, Companion animal
Subject Terms: Diet/rations/food, Endocrine/autocrine/paracrine, Thyroid, Trace elements, Nutrition/metabolism
Article class: Scientific Article

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Abstract: Excessive or deficient intake of iodine may play a role in the development of goitre and hyperthyroidism in cats. Previous investigations have shown that the serum free thyroxine level of cats is affected by brief administration of food high or low in iodine content. We have now measured serum free thyroxine levels in groups of cats fed relatively high or low iodine diets for much longer periods (5 months). In contrast to our earlier findings, the chronic ingestion of relatively high or low iodine diets did not lead to statistically significant differences in serum free thyroxine levels. The results of the present investigations show that the cat is able to maintain normal levels of thyroid hormone despite prolonged high or low iodine diets. It may be that the adaptive mechanisms that are called into play during chronic high or low iodine intake lead to thyroid disease, particularly in certain predisposed individuals.

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