Crikey, that is very young to be hyper-t - are you looking to operate if her chest will allow it? I had a hyper-t cat this year but I couldnt pill him, and he had other health issues, so an op wasnt an answer - I have another one that is borderline and if his ever turns, it will be the op as soon as possible, he hates pills. Tino was sick on Felimazole, so he ended up on Vidalta, but I hardly got any into him and he did end up with diarrhea, although he had liver issues too, so it could have been that. Fingers crossed for her