I have a 10 year old male neutered cat. He has a growth or cyst on the side of his throat. He seems happy go lucky....but if you feed him anything but Iams, he throws up and has alot of diarrea. Maybe he's just a sensitive cat that can't have anything but his iams but the cyst or what ever it may be, well, I'm guess I'm just lost. I'll probably be taking him in to get looked at but as he's older and if it's cancer or something and they would want to take it out, I just can't put him through that. I can't imagine it would be some kind of thyroid thing or something...I just don't know...any suggestions? THANK you!