Interesting! Bless Tex's little heart. Actually, thyroid treatment was one of the topics discussed in this month's CatWatch from Cornell Univ of Vet Medicine newsletter that I receive in the mail.

I recall it saying something like it is one of the safest treatments you can give your cat and it is a one time only treatment, but there is a quarantine time after the treatment because of the Iodine 131 being radioactive(somewhere usually around 9 days).

I think I recall the article also mentioning that vomiting is a symptom of hyperthyroid. If you would like, I could re-read the article and sum it up here for you
Give Tex some scritchies for me
**hugs**
Karen