Efficacy of Low‐dose (2 millicurie) versus Standard‐dose (4 millicurie) Radioiodine Treatment for Cats with Mild‐to‐Moderate Hyperthyroidism

• DOI: 10.1111/jvim.14646
• Publication Date: 2017-02-03T13:44:07Z
• Authors: J.M. Lucy; M.E. Peterson; J.F. Randolph; P.V. Scrivani; M. Rishniw; D.L. Davignon; M.S. Thompson; J.M. Scarlett
• Keywords: Azotemia; Subclinical infection

Radioiodine (131 I) is effective treatment for hyperthyroidism in cats, but optimal dose to restore euthyroidism without inducing hypothyroidism unclear. Treatment-induced can lead azotemia and reduced duration of survival.To compare efficacy short-term outcomes low-dose 131 I versus higher, standard-dose as hyperthyroidism.A total 189 client-owned cats undergoing mild-to-moderate (serum T4 ≥ 4.0 μg/dL <13.0 μg/dL).Prospective, nonrandomized, cohort study comparing with either (2 mCi, n = 150) or (4 39) I. Serum , thyroid-stimulating hormone (TSH), creatinine concentrations were measured after 1, 3, 6 months determine persistent hyperthyroidism, overt (low high TSH), subclinical (normal azotemia.There was no significant difference prevalence between standard- groups at 3 (0% 5.3%; P .34) 3.3%; .51) months. Overt (18% 1%; .0005) (46% 21%; .004) more common No incidence existed groups, treated had higher (P < .05) percent rises .0001).Low-dose safe evidenced by a cure rate >95% frequency iatrogenic azotemia.