I want to say I am so sorry to hear about your kitty being sick. I have a sick one myself, and the decisions we are forced to make are never easy. On Halloween, my cat hercules was found in my garage not breathing well and very lethargic. I rushed him to the emergency vet because he was so sick, and they basically refused to help him unless I agreed to do thousands of dollars worth of tests. Just as I was telling the vet what to do, Hercules passed away. I have spoken to several vets and they gave some suggestions that would explain his symptoms (which are very similar to your cat's). Could your cat have been exposed to any poisons in the house? Is he an indoor or outdoor cat? Cats that are exposed to poisons have problems breathing, they are lethargic, vomiting, and have dilated pupils. The other suggestion was that Hercules had somehow contracted heart worms - even though he was an indoor cat only. Heart worms also cause fatigue, dilated pupils, labored breathing, and appetite suppression. Lastly, there is heart disease and cancer. I would look at some of the threads done by Medusa. She has cats who have suffered from heart disease etc., and have given them a wonderful life. I agree with everyone about seeking the opinion of a another vet. When I was unhappy with the treatment of my cat Sydney who has nasal lymphoma, so I switched vets three times before I was satisfied. I am so happy I changed and the only reason she is still alive and happy is because I changed. It made all of the difference. First you need to figure what is wrong with your baby, and some x-rays and blood tests are very helpful -also typically not too expensive. It is much easier figuring out what to do, if you know what you are working with. Please keep us updated on how he is doing.