Wakeling, J., K. Moore, et al. (2008). "Diagnosis of hyperthyroidism in cats with mild chronic kidney disease." Journal of Small Animal Practice 49(6): 287-294.
It is a well known phenomenon that hyperthyroid cats with concurrent non-thyroidal illness, such as chronic kidney disease (CKD), may have total thyroxine concentrations within the normal reference range. This causes a diagnostic dilemma. The objective of this study was to determine total thyroxine, free thyroxine and/or thyroid-stimulating hormone concentrations in cats with mild CKD. Three groups of cats were included: 16 cats with CKD and clinical signs compatible with hyperthyroidism but total thyroxine within the reference range (these cats were confirmed with hyperthyroidism at a later date); 20 cats with CKD and no signs of hyperthyroidism; 20 clinically healthy senior cats (over 8 years of age). Four of the 20 cats with CKD had free thyroxine concentrations that were borderline or high. Of the 16 cats with hyperthyroidism and CKD, free thyroxine was high in 15/16 cats and thyroid-stimulating hormone was low in all cats. The researchers conclude that the combined measurement of free thyroxine with total thyroxine or thyroid-stimulating hormone may be of merit in the diagnosis of hyperthyroidism in cats with chronic kidney disease.
>> PubMed abstractRelated articles:
Langston, C. E. and N. J. Reine (2006). "Hyperthyroidism and the kidney." Clin Tech Small Anim Pract 21(1): 17-21.
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chronic renal insufficiency
chronic renal disease