Hyperthyroidism Treatment Options

There are three options for the treatment of hyperthyroidism in cats: See for yourself how radioiodine compares to medical or surgical treatments
	Radioiodine	Long-term medical management	Surgery (thyroidectomy)
Cure rate	Highest cure rate	Never cured, only controlled. Cat's thyroid tumor continues to grow and may transform into cancerous tumor with time	Hyperthyroidism will persist or recur unless all thyroid tumor tissue is removed. Can be difficult for surgeon to remove tumor tissue if located within chest cavity
Ectopic thyroid tumors (not located in the expected site in the neck; generally within the chest cavity)	Destroys thyroid tumors regardless of location	Generally controls hyperthyroidism but thyroid tumor continues to grow and may transform into cancerous tumor with time	Can be difficult for surgeon to remove tumor tissue if located within chest cavity
Thyroid carcinoma (cancer)	Only treatment that can destroy thyroid cancer that has invaded and spread throughout the body	Thyroid carcinoma will continue to grow, invade, and spread throughout the body	Very difficult to completely remove all cancerous tissue
Convenience for cat and their family	Most convenient; single injection cures the disease	Life-long daily medication. Damage to your relationship with your cat possible due to the difficulties of pilling your cat several times daily.	Invasive surgery and hospitalization
Risks, side effects, and complications	No side effects or risks	Side effects common, including lethargy, loss of appetite, or vomiting. Less common include severe itching reaction, liver failure, and adverse effects on the bone marrow	Many potential complications associated with anesthesia and surgery. Postoperative low calcium (calcium crisis) can be life threatening.
Hypothyroidism	Rare with patient-specific dosing	May result in hypothyroidism, as low T4 is common. Veterinary visits can result in dosing adjustments.	Very common immediately after surgery
Life-long medication	No	Yes	Sometimes
Aftercare	Routine care	Continual monitoring and blood tests at 3- to 6-month intervals are necessary during long-term treatment.	Intensive (ICU monitoring, pain medication, antibiotics)
Concurrent diseases	Effective treatment for pets with other disorders or diseases	Generally still effective treatment although pet owners should look out for adverse drug-drug interactions	Unlikely to be good surgical candidate
Recurrent hyperthyroidism	Uncommon	Common; as disease advances and tumor grows, relapse expected	Common if all thyroid tumor tissue is not removed
Survival time	Longest	Shortest	Intermediate
Cost	No surprise costs or additional charges	Over long-term, most expensive option (continuing vet visits, blood tests, drug costs)	Expensive (ie, surgery, anesthesia, hospital time, and ICU aftercare)