My cat, 17 yo male, has hypertyroidism. We discovered few months ago and since then we are keeping it under control with pills. Main symptoms were loss of weight and frequent throwing up, but since he is taking the pills he got back some weight and does not puke anymore. He seems to be hyper sensitive to the T4, as soon as the value increases a bit, the symptoms are back. It took a while to find the correct dosage, but now he is ok with 5 pills in 3 days. Kidneys are holding up well according to the last vet visit. However, since one week, he started to loose weight again, and pukes liquids and foam almost regularly, once per day. Can it be that the condition worsened and the dosage has to be increased?