my gp is not eating

Question
My 4 years old gp is not eating. He cruches into a ball and refuses any food. I noticed that he was not eating three days ago because his food was untouched and there was not many droopings in his cage. Since then I have been feeding him with a syringe. I do not know if I am feeding him enough. He had been pooping but not peeing. I have checked for bloating but I don't think it is the problem. I have been giving him cramberry juice (in case of UTI) and vitimin c along with blend of pellets, vegetables and oatmeal. Since he is not urinating,  I am afraid to give him more fluids in case of kidney stones. Last night he started breathing heavely, Am I causing damage to his lungs? Can you help me?  

Answer
He most likely has pneumonia or an upper respiratory infection. He will need to see a vet to get antibiotics as soon as possible. He most likely has fluid in his lungs, and most likely soon he will have so much that he will start convulsing, and eventually die. I have some supportive care that you can try on my website, http://woopets.bravehost.com , but he will need to see a vet to live through this.
Brittany