Hyperthyroidism is the most common endocrine disorder in cats over age 10. Multiple treatment options allow individualized management for improved quality of life.
Feline hyperthyroidism significantly compromises quality of life through weight loss, gastrointestinal symptoms, hypertension-related complications, and the cardiovascular effects of chronic elevated thyroid hormone. Early diagnosis enables treatment before severe complications develop, and most treated cats return to excellent quality of life. Treatment choice should be individualized based on the cat temperament, owner lifestyle, concurrent conditions, and accessibility of specialist services. Daily medication is effective but requires consistent owner administration and regular monitoring. Radioactive iodine is curative but requires a period of isolation post-treatment that stresses some cats. An important consideration is that treating hyperthyroidism may unmask pre-existing kidney disease as GFR normalizes — pre-treatment kidney assessment should guide treatment decisions.