The aim of this study is to determine the occurrence of creatine kinase (CK) serum activity in cats with hyperthyroidism and its associations with clinical-pathological alterations and with total (TT4) and free (FT4) thyroxin. CK serum activity was evaluated in 19 cats with spontaneous hyperthyroidism, with TT4 ranging from 34.88-294.98nmol L-1 and FT4 ranging from 2.83-52.9pmol L-1 and also by serum biochemical analysis, including the activity of CK, alanine aminotransferase (ALT), alkaline phosphatase (ALP), aspartate aminotransferase (AST), gamma-glutamyl transferase (GGT), cholesterol and bile acids. The reference value for CK considered in this study was of 110-250U L-1. CK serum activity was evaluated in 19 cats with spontaneous hyperthyroidism, with TT4 ranging from 34.88-294.98nmol L-1 and FT4 ranging from 2.83-52. 9pmol L-1. Its activity CK was elevated in 47.3% of cats (≥250U L-1) and presented statistical difference (P<0.05) between cats with or without cardiac disease. CK presented weak association with all parameters in biochemical analysis. In this study, it was not possible to establish a clear association between hyperthyroidism and the increase of CK. However, it is important to highlight the inclusion of CK activity in the routine examinations for the evaluation of hyperthyroidism and for further studies to be developed.
thyroid; cats; cardiac disease; thyroxine.
