Radioactive Iodine Therapy

Radioactive Iodine Therapy to Treat Hyperthyroidism

Hyperthyroidism is one of the most commonly diagnosed diseases in cats. Generally afflicting older cats greater than 9-10 years of age, the disease can be seen in cats as young as 5 years old. 

What is Hyperthyroidism?

In most cases, hyperthyroidism is caused by a growth of abnormal, non-cancerous cells in the thyroid gland which secrete thyroid hormones in excess of the normal levels.

If left untreated, a hyperthyroid cat can exhibit any, or all, of the following signs:

  • extreme weight loss
  • excessive appetite
  • muscle weakness
  • heart disease
  • intolerance to stress

If left alone long enough, the disease will eventually lead to death.

The Treatment

The success rate of Radioactive Iodine (I-131) in treating hyperthyroidism is approximately 95-98%. A few patients may require an additional treatment with I-131 if they do not return to normal thyroid function within 3-6 months. A small percentage of cats may become hypothyroid, meaning they do not produce enough thyroid hormone. If this occurs, it is commonly a temporary finding, or in rare cases, can be easily resolved with supplementation.

Administering Treatment

The protocol for administering radioactive iodine is a single injection below the skin, given between the shoulders.

The patient is then hospitalized at least 5 days to monitor the radioactive emissions and to observe for any adverse effects. The cat is well cared for during this time, and will receive personal attention from one of our dedicated staff members multiple times a day with feeding, watering, litter changes, and cage clean-ups.

Once the emission readings reach a level that is set by the Florida Department of Health, the patient is released home. Upon discharge, the owner will be provided instructions for home care for two weeks. Limited interaction, specialized disposal of litter, and temporary seclusion are standard at-home protocols for the first two weeks following this procedure. This is to ensure the safety of the public.

Feel free to discuss these instructions with a member of our staff during the consultation.

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