Thank you for considering making an appointment at AVMI for radioiodine therapy for your cat's hyperthyroidism. Our goal is to provide the highest quality service in a timely fashion. In general the referral process is expected to proceed as follows:

  • Your referring veterinarian diagnoses your cat with hyperthyroidism, usually based on a blood test and physical exam findings, and refers you to AVMI for radioiodine therapy.
  • Ideally, your referring veterinarian provides you with a completed AVMI request form and copies of the supportive patient medical records.
  • You contact AVMI to schedule an appointment for the radioiodine therapy.
  • AVMI creates a digital medical record for you and your cat to which copies of the previous medical records information can be attached.
  • If you were not provided with a completed AVMI request form and/or copies of your cat's medical records, AVMI will  send your referring veterinarian a medical records request form for your cat.


Pretreatment Recommendations

While not inexpensive, it is well established that because radioiodine therapy actually cures your cat's hyperthyroidism, ultimately it is the least expensive treatment option and therefore a good investment in your cat's long term health. Like most investments, it is typically preceded by a certain amount of  "due diligence". At AVMI there are NO absolute pre-radioiodine therapy requirements, as each patient is unique and each client's resources will vary. Never-the-less, there are certain tests the results of which provide a comprehensive understanding of the overall condition of the patient and allow us to ensure a more consistently favorable outcome following radioiodine treatment. These tests include:

Laboratory Tests
  •   CBC
  •   Serum Chemistry
  •   Serum Electrolytes
  •   T4
  •   FELV & FIV screening
  •   Urinalysis

These tests are generally performed by your primary care veterinarian to ensure your cat is a good candidate for referral for radioiodine therapy and copies of the results are provided as part of the referral process. Depending on a number of factors including but not limited to 1) the results of these tests, 2) the interval between the date these tests were performed and the admission date for radioiodine therapy, and 3) the condition of the cat at the consultation appointment, repeating any and/or all of these tests as well as performing other tests not included in this list may be indicated. If additional testing is indicated at the time of admission the indicated tests and their costs will be included in an itemized estimate that will be provided at the end of your consultation appointment.


The short lived radionuclide we use for the thyroid scintigraphy expires within approximately 4 hours of calibration. To enable us to perform the imaging procedure on the day of admission, we order the radionuclide the day before. Confirmation of payment in the form of a credit card number is required when scheduling these appointments. A charge for the cost of the radionuclide will be made to the credit card for failure to keep a scheduled appointment for a nuclear medicine procedure unless you cancel 24 hours before your appointment. Your credit card information is deleted from our system at the time your cat is admitted for the radioiodine therapy.

Patients with contagious diseases

Cats suffering from upper respiratory viruses are often highly contagious to other cats. PLEASE notify us ASAP before hospitalization, if your patient is demonstrating symptoms of an upper respiratory virus (e.g. sneezing, congestion, nasal or ocular discharges) or if your patient has a history of chronic respiratory virus infection. Appropriate isolation of these cat’s is the only way to avoid unnecessary spread of the virus to other feline patients in our care. We have a separate radioiodine isolation ward that can be utilized for this purpose.


The cats treated with radioiodine usually remain hospitalized for a total of between 3 and 6 days following radioiodine therapy. The duration of the cat’s hospitalization will be determined by the radioiodine dose as well as the cats rate of radioiodine excretion. The date of discharge from the hospital can only be estimated at admission.

Safety precautions

Clients will be advised to follow specific radiation safety precautions once their cat is returned to them. In brief these instructions include the use of a flushable/clumpable cat litter and the limited interaction between client and their cat for a precautionary period of approximately 12 days following discharge.

iCat Webcams

Because both California state and Federal regulations prevent visitation of cats treated with radioiodine during the mandatory hospitalization period, AVMI has installed individual iCat web cams for each of the Snyder Cat Cottages utilized by the hyperthyroid cats treated with radioiodine in our facility. These personal iCat web cams allow interested clients and referring veterinarians to continually observe individual cats hospitalized for radioiodine therapy at our facility.