Success rate of I-131 is over 95% with just one injection and, if a second is required and the thyroid is not cancerous, it is almost 100% effective. I-131 is nearly painless, very well tolerated and side effects are rare.
Laboratory tests should be performed 1 and 3 months after I-131 administration to assess the thyroid as well as the kidney values. All follow-up lab work should be performed by your referring veterinarian. If the thyroid remains hyperactive after 3 months and an additional injection is required, our clinic will give this injection at no additional cost to you.
One of our doctors will discuss take home instructions with you on the day your cat is admitted for treatment and a written version will be sent with you at the time of your cat's discharge.
The take home instructions are as follows:
Your cat has been treated with radioactive iodine and still possesses a low level of radioactivity which is detectable for up to the next 14 days. The present level of radioactivity has been measured to be below the maximum level set by the regulatory agency and though strict isolation is not necessary, for the first 3 days, contact with the cat should be limited. Remember that, although the levels of radiation present in your cat have no medical consequence to you, the limited exposure to your cat, is necessary to decrease your life-long cumulative exposure to radiation.
Following discharge from the hospital:
• The cat should be kept inside for 2 weeks
• The cat should not be permitted to have prolonged contact with children under the age of 12 for
3 days following hospital discharge
• Pregnant women and women who are breastfeeding should avoid any contact with the cat and
its urine / feces for at least 3 days after discharge.
• Family members should not be permitted to sleep with the cat for 3 days after discharge. They
also should limit close contact with the cat (being within 1 foot of the cat) for the next 3 days to no
more than 30 minutes per day. Again, this is to limit your lifetime cumulative exposure.
• For the next 2 weeks following discharge use scoopable and flushable litter and either flush
properly or store the waste. Wear disposable gloves when handling the litter. Scoop the waste
from the box 1-2 x daily and either store it for 80 days (people with septic systems) or flush the
waste down the toilet (remember, use only flushable litter if you are planning to flush the waste!).
If you plan to store the waste, place it in a plastic bag and place the bag in a 5 gallon bucket with a
lid and store it in an out of the way place for 80 days. Do not throw in the trash for 80 days as this
may result in alarming radiation detectors at the sanitation department and may result in a large
fine to you.
• Wash your hands thoroughly after handling your cat, your cat's food dishes and the litter pan.
Please feel free to call us at 509-535-6369 to discuss any concerns regarding radiation safety or I-131 treatment.
The Cat's Meow Feline Veterinary Clinic and Hyperthyroid Treatment Center
1017 South Perry Street
Spokane, WA 99202
(7:30 drop off)