Petco Text Logo
Petco Pet Logo
  • Two Easy Ways to Start Earning Rewards!

    rewards header
    Become a member today!
    Members-only pricing and offers, personalized care notifications, Vital Care points back on every purchase and more!
    Petco Pay LogoBecome a credit card member today!

    Earn 2X Pals Rewards points at Petco
    when you use Petco Pay!

    APPLY NOW
    Learn More About Petco Pay Benefits

My cat has hyperthyroidism. Is A131 safe? How long is quarantine?

Updated on September 23rd, 2025

Pet's info: Cat | Mixed Breed | Male | neutered | 13 years and 6 months old | 14 lbs

My 13 year old cat was just diagnosed with hyperthyroidism. The research online suggests that the A131 treatment is a safer option bc there are no side effects and it’s a curative solution. Are there really no risks to this treatment? Also, I read they have to be quarantined but I cant find anywhere that says for how long. What are your thoughts on that treatment option? My cat does have a heart murmur and slight wall thickening but just had his third echocardiogram and is not yet on any meds.

1 Answer

Most Helpful Answer

C. Rathjens, DVM

Answered By C. Rathjens, DVM

Veterinarian

Published on December 15th, 2018

The radiation is good treatment option, however it's important start with the oral pill (methimazole) first to make sure his body tolerates having lower thyroid levels first. When we get the thyroid disease under control sometimes we uncover kidney disease that was always there. The other down sides of A131 are cost, availability of the treatment (you have to go to a facility, this isn't something your vet can do), and the process (needing to stay at the facility, I believe it's 3 days but you'd have to check on the protocol at your local facility).
Vote Icon1Pet Parents found this answer helpful

Smart Picks for Smart Questions

Have A Vet Question?

Book an appointment with the pros – our expert vets are here to help.

Share

Styled arrow button