For Referring Veterinarians

For more information on cat thyroid disease, check out this pet information article at

I-131 is the recommended choice for cats with hyperthyroidism. The advantages of I-131 are:

I-131 works best in the stable hyperthyroid cat without other significant diseases (renal, gastrointestinal, cardiovascular, other endocrinopathies). If your patient has a significant other disease, please contact us to discuss whether I-131 is appropriate for your patient.

The referring veterinarian performs ALL the pre-treatment and post-treatment testing. As part of our service, we offer consultations with the referring vet prior to treatment and for three months post-treatment.

We only accept I-131 patients from a referring veterinarian.

Click here for the Primary Care Veterinarian Referral Form.

Click here for Referring Veterinarian Information and Work-up Instructions.

Please review these important facts about an I-131 referral.

  1. Your pre-therapy workup needs to consist of the following items. We need copies of these results (including x-rays) along with any pertinent medical records.
      • Complete Blood Count (within 60 days of admission)
      • Biochemical Profile including BUN, creatinine, ALT, SAP, Na, K (within 60 days of admission)
      • Urine sample analysis (within 60 days of admission)
      • T4 within 30 days of the I-131.
      • VD (or DV) and lateral thoracic radiographs.
      • If the patient is currently on methimazole -- and has been for more than 90 days -- we require a T4 taken 7 days after cessation of this medication. If you have questions, we can suggest a schedule for stopping, being retested, and arriving for therapy.
      • Please supply all previous T4 values, histories of biopsies, cancer, & acute episodes.
      • For peace of mind of our staff, and in accordance with New Hampshire State law, cats need to be current on their Rabies vaccination.
  2. Patients MUST be off methimazole for at least seven days prior to admission for I-131 therapy.
      • Other medications which may interfere with therapy include: ACTH, Anticoagulants, Antihistamines, Antiparasitics, Bromides, Butazolidine, Mercurials, Nitrates, Penicillin, Pentothal, Perchlorate, Salicylates (large doses), Sulfonamides, Thiocyanate, and some Vitamin preparations.
  3. Patients are hospitalized in the nuclear medicine ward for approximately seven days. Due to State and Federal radiation rules, clients cannot visit patients during therapy, nor can patients be removed from the ward until officially released. Clients cannot terminate therapy or arrange for early release once therapy has begun.

  4. After admission for I-131 therapy, information on a patient's daily status will be given by our personnel if the owner requests.

  5. Our I-131 consultation includes:
      • Review of all pertinent case records and radiographs;
      • Administration of I-131, radiation monitoring, and hospitalization in the nuclear medicine ward;
      • Daily care and feeding (and as much love as we can safely give);
      • Three month and/or as needed follow-up consultations regarding test results between us and the referring veterinarian.
  6. Not included:
      • Diagnostic tests performed at your clinic prior to therapy;
      • Emergency medical tests, procedures, or medications needed during the patient's hospitalization for therapy;
      • Post-therapy T4 determination performed at your clinic.
  7. Patients are released to owners according to State and Federal rules.
      • Patients will be excreting a small amount of I-131 on dismissal. Clients are instructed before admission -- and given written instructions -- on handling of patients for two weeks post-release from therapy. A litter disposal kit consisting of clumping, flushable litter, latex gloves, and a litter scoop, is given to clients. If clients are unable or unwilling to comply with these precautions, they should consider surgical or medical management.
      • If a patient requires medical attention or hospitalization during the two weeks immediately following treatment, please contact us.
  8. Possible but very rare complications of radioiodine therapy include:
      • Patients may become hypothyroid. Rare cases may need exogenous thyroid supplement.
      • Sore throat, dysphagia. This is usually transient, but a permanent voice change is possible.

Toll free 1-877-929-1199  Phone 603-227-1199   1 Intervale Rd. Concord, NH 03301    Email Us