My 15.5 year old cat is two weeks into treatment for hypothyroidism. After 10 days of tablets, he started vomiting, then lost his appetite. Dosage was reduced and he was switched to transdermal. Still not eating. Vet prescribed appetite stimulant. Still vomiting. Diarrhea now. Will his side effects eventually subside? Anyone have good experience with a natural treatment? These side effects are devastating.