Pre-treatment diagnostics and patient evaluation

Required pre-radioiodine diagnostics include the following diagnostic tests within 30 days of treatment, preferably from a major veterinary laboratory (IDEXX or Antech):

  • CBC
  • Chemistry Profile
  • T4 (must indicate an exact number from a veterinary laboratory - if done in house, there must be a specific reading; i.e., '>4' is not sufficient)
  • Urinalysis, +/- urine culture (urine culture if suspicion for UTI)
  • IDEXX SDMA (if available)
  • Blood pressure
  • Chest radiographs (minimum 2 views, ideally 3 views)
  • Abdominal radiographs +/- abdominal ultrasound (most applicable to patients suspected to have, or known to also have, significant non-thyroidal abdominal disease)
  • Echocardiogram (if suspicion for moderate to severe heart disease, and/or if concern that cat may experience CHF while hopitalized post I 131 treatment)

If the cat has been on methimazole or other medical management treatment (carbimazole, PTU), prior to radioiodine administration, we require the cat to have been off the medication for at least 7-14 days prior to I 131 treatment (or, if on YD diet, we ask that the cat have been off the Hills Y/D diet for 8 weeks), and a T4 level at least 7 days after cessation of methimazole/YD.

Previous records, including the information above (including date of diagnosis of hyperthyroidism and T4 when initially diagnosed), along with other pertinent patient information (weight history, surgeries, biopsies, communication with owner regarding hyperthyroidism/radioiodine, etc.) can be FAXed to VCA Cat Hospital of Chicago at 773-478-0605, or emailed to Dr. Currigan using the Contact form.