Treatment of thyroid problems with radioactive iodine

The treatment of hyperthyroidism in cats with radioactive iodine takes a total of six days, as mandated by Dutch law. You will receive daily updates about your cat via phone, email or Whatsapp.

At Lingehoeve Diergeneeskunde, we follow a specific procedure that prioritizes a cat-friendly approach, striving to perform all examinations and treatments without sedation whenever possible.

Day 1 – Thyroid scan + radioactive iodine
The first day of treatment, a thyroid scan called scintigraphy is made. Using a gamma camera, we are able to locate the overactive thyroid tissue. Using this thyroid scan, we can determine whether the cat suffers from hyperthyroidism and which amount of radioactive iodine has to be administered.

The same day, the cat will be injected with radioactive iodine. This slows down the function of the thyroid, lowering the amount of thyroid hormones produced: the hyperthyroidism disappears.

Day 2 – 6 -  bloodwork thyroid, kidneys and blood pressure
From Tuesday to Monday the cats stay in our special nuclear facility, because of the radiation. On Friday blood will be drawn to check thyroxine (T4) and kidney function (creatinine, urea) and blood pressure will be checked. High blood pressure is often seen in cats with hyperthyroidism.

Day 7 – The cat goes home
On day 7 treatment is completed and the cat can go home.

Day 1 – Thyroid Scan and Radioactive Iodine Treatment
On the first day of treatment, a thyroid scan, known as scintigraphy, will be conducted. Using a special camera, we can locate the overactive thyroid tissue. This scan helps us confirm whether the cat is suffering from hyperthyroidism and determines the appropriate amount of radioactive iodine to be administered.

On the same day, the cat will receive an injection of radioactive iodine, effectively alleviating hyperthyroidism.

Days 2 – 6 – Bloodwork, Thyroid, Kidneys, and Blood Pressure Monitoring
From Tuesday to Monday, the cats will stay in our specialized nuclear facility due to the radiation. On Friday, blood samples will be taken to assess thyroxine (T4) levels, kidney function (creatinine, urea, SDMA) and blood pressure, as high blood pressure is often observed in cats with hyperthyroidism.

Day 7 – Discharge
On day seven, treatment is completed, and the cat is ready to go home.

Follow-up
When your cat returns home after treatment with radioactive iodine and hospitalization, several precautions must be observed. For the next three weeks, your cat should avoid contact with pregnant women and children under the age of 18. Additionally, your cat must remain indoors for three weeks for safety reasons.

Contact with radiation primarily occurs through the cat's urine, feces, and saliva, so it is advisable to minimize cuddling with your cat during this period. You will need to collect the litter for three weeks and then store it for an additional four weeks. After this seven-week period, the waste will have lost its radiation and can be disposed of with regular trash.

We recommend completely changing the litter box every other day and removing soiled areas daily. Please remember to wear gloves when cleaning the litter box.

Check-up thyroid, kidneys and blood pressure
After treatment with radioactive iodine, it can take several months for the thyroid gland to stabilize and for the cat to reach a new normal balance. This process may take up to six months. Therefore, we can determine definitively whether the treatment was successful only after this period. For this reason, we recommend checking thyroid hormone levels (T4), kidney function (urea, creatinine, SDMA), and blood pressure six months after treatment. This bloodwork can be performed by your own veterinarian.

Costs
The total thyroid treatment for your cat includes a thyroid scan, radioactive iodine treatment, admission to our specially equipped nuclear facility, multiple blood tests, and a blood pressure measurement. The cost for this complete package is €1.825 (effective January 1, 2025). While this may initially seem high, it is important to understand that this one-time treatment with radioactive iodine is often more cost-effective than alternatives such as one or more surgeries or lifelong medication, which requires regular blood tests. Therefore, for cats with thyroid problems, this treatment can be a beneficial choice both financially and medically in the long term.