Serum thyroxine (T4) and triiodothyronine (T3) uptake values in normal adult cats as determined by radioimmunoassay.

Radioimmunoassay procedures employing highly specific antibodies for either serum T4 or T3 were utilized to determine T4 concentrations and T3 uptake values in normal cats. Mean values for serum T4 and for T3 uptake were 30.9 ng/ml +/- 19 ng/ml and 59.67% +/- 12.2%, respectively.