TREATMENT OF FELINE HYPERTHYROIDISM USING ORALLY-ADMINISTERED RADIOIODINE - A STUDY OF 40 CONSECUTIVE CASES

Forty cats with hyperthyroidism were treated using 200 to 300 (typically 250) mBq of orally administered I-131. Thirty-six cases (90%) were successfully treated, as assessed by resolution of clinical signs and reduction in plasma thyroxine concentrations to normal or reduced values after treatment. Although higher doses of I-131 appear to be required when the radioisotope is administered orally rather than intravenously, a less stressful administration procedure and greater availability of therapy capsules offer useful advantages for treating thyrotoxic cats.