Changes in serum symmetric dimethylarginine (SDMA) concentrations after treatment of feline hyperthyroidism with anti-thyroid medications

Objectives: To report changes in serum creatinine and symmetric dimethylarginine (SDMA) concentrations following treatment of feline hyperthyroidism with anti-thyroid medications and compare these biomarkers at baseline between cats that were and were not azotaemic after treatment. Methods: Retrospective study; hyperthyroid cats that were euthyroid (total thyroxine concentration (TT4) 7-40 nmol/L) at 1 month (T1) and/or 2-9 months (T2) following treatment were identified and grouped by renal status defined by serum creatinine concentrations post-treatment. Comparisons were made using non-parametric statistics, and the correlations assessed using Spearman’s correlation coefficient. Data are presented as median [minimum-maximum]. Results: Nineteen hyperthyroid cats were included. At baseline, TT4 was negatively correlated with serum concentrations of creatinine (rs = -0.73; P