EVALUATION OF THE ANALYTICAL PERFORMANCE OF AN ENZYME IMMUNOMETRIC ASSAY (EIA) DESIGNED TO MEASURE ENDOGENOUS THYROID-STIMULATING HORMONE (TSH) IN CANINE SERUM SAMPLES

The analytical performance of a commercially available enzyme immunome tric assay (EIA) designed to measure endogenous thyroid-stimulating ho rmone (cTSH) concentration in canine serum samples was evaluated. The precision of the assay was acceptable with intra- and inter-assay coef ficients of variation (CV) of 5 and 11%, respectively. The assay maint ained linearity under dilution and recovered added cTSH in a linear an d proportional manner. The limit of detection (0.03 mu g/L) was well b elow the values measured in serum from dogs with primary hypothyroidis m (median value 1.52 mu g/L). Further, the assay clearly distinguished dogs with primary hypothyroidism from clinically healthy dogs (P = 0. 0004). Based on these findings, it was concluded that the analytical p erformance of the assay was acceptable.