I-131: The Gold Standard of Hyperthyroidism Care

I-131 is both the primary and most preferred therapy option by veterinarians to successfully treat and cure hyperthyroidism. I-131 has the highest success rate with stable hyperthyroidism in cats). With one injection of I-131, abnormal thyroid tissue will be eradicated in over 98% of cases leaving your feline family member healthy for years to come.

I-131 offers many advantages over other treatment options that include:
  • No anesthesia required
  • Normal thyroid or nearby parathyroid tissue is not impacted
  • No lifelong daily medication
  • Most cost-effective therapy
Expertise you can trust

Your cat’s I-131 treatment will be performed by Dr. Michael Dutton, founder of Hopkinton Animal Hospital with a 15-year track record of performing over 2,000 successful I-131 treatments. Annually, Dr. Dutton treats about 100 cats resulting in positive health outcomes having been the leading expert in the area since 2007.

Alternative treatment options:

Even though I-131 is the gold standard and best treatment option to cure hyperthyroidism, there are alternative treatments spanning daily medication, surgery and diet. However, all have lower success rates, as well as higher costs when comparted to I-131.

  • Anti-thyroid Medication (Methimazole)
    • Disease is managed with daily medication that can have serious and fatal side effects
    • Average life expectancy is 3.5 years
    • Long-term effects can damage kidneys and liver
    • Yearly cost of $500-700 for the rest of your cat’s life will exceed total cost of I-131
  • Surgery
    • Difficult to perform due to location of the thyroid — high risk to vital parathyroid glands
    • One gland needs to be removed at a time — 80% will still develop a tumor in remaining thyroid gland within 12-18 months
    • Cost of two surgeries is $1,600-$3,000; most likely two are needed
    • When surgery fails, I-131 is the preferred next step
  • Hills Prescription Diet. Ultra-low iodine diet (Hills y/d)
    • Diet can lower thyroid levels to normal range, but tumor continues to grow in cat who needs to be 100% on the diet — some will not eat it
    • Multiple cats in the home will mean all the cats need to be on the diet to prevent any iodine being introduced to the affected cat
    • Long-term testing (>5yrs) on affected cats remains unknown as well as the effects of the diet on normal cats
    • Hills Prescription Diet is expensive to maintain, ranging from $380 to $1,460 annually
New Hampshire i-131 at Hopkinton Animal Hospital provides treatment for hyperthyroidism in cats and guinea pigs