There are four treatment options for feline hyperthyroidism: medication, radioactive iodine therapy, surgery, and dietary therapy.
a) Medical Treatment–
consists of the administration of methimazole (Felimazole®) up to three times daily. The drug blocks the secretion of T4 but does not remove the tumorous thyroid gland. The drug is given for the rest of your cat’s life.
removes the affected thyroid gland or glands and will cure hyperthyroidism.
c) Low Iodine Diet–
Hill’s Prescription y/d. Feeding the y/d diet will help to manage your cat’s hyperthyroidism but will not cure the disease.
d) Radioactive Iodine I-131–
will cure hyperthyroidism and is a single, under the skin injection.