Paco my puppy

My 8 month old puppy recent became sick about two weeks ago. We  thought it was something In his mouth being that he wouldn’t eat and had difficulty opening and closing his mouth. He was taken to Dr. V at forest animal hospital, sedated and had his mouth checked. The vet said nothing was wrong with his teeth or gums. He did have fever so he was given antibiotics and the vet told us we would have to take him to an animal hospital in tinton falls New Jersey if he doesn’t respond to the antibiotics. We are praying nothing serious I’d wrong but in case we have to take him for more tests it is estimated to cost anywhere from 750 to 1000 dollars for the other tests. 
We are asking for help because we have already spent 500 dollars and will not be able to
afford more testing. Any donation will be greatly appreciated.