Hello Sus,
I am so sorry to read all that has happened w/ Bella. You must be exhausted as well, it is so terrible when our furkids are ill and can't tell us anything.

I have had 3 cats diagnosed with hyperthyroid, and all were prescribed the Thiamasole. I never had any of the issues you describe with Bella.

As such, I don't really have any help to offer to you.

How old is Bella? One of mine was 8, the other 2 were in the mid teens.

How does she feel to you? Very very thin? I mean, the Dec weight of 4ooo grams / 8 pounds is a small cat. Now she is down to 7 pounds and a bit. Is her spine all bony? Or is it still covered?

Is she dehydrated? Has she been given and subcutaneous fluids?


Oh, for others reading: 4000 grams is 8 pounds 13 ounces. 3300 grams is 7 pounds 4 ounces.