snake illness??

Question
my sons 3 year old cornsnake hasnt eaten in 3 months. At first i thought it was mating season and he wasnt eating through that but now he has gotten weaker and whistles when he breaths. Im a single parent and couldnt afford to pay a vet much and RSPCA in my town dont treat reptiles so im faced with a dilemma. Any help would be greatly appreciated. Thanks for taking the time to read and respond.
David

Answer
Sounds like a respiratory infection.  Increase the heat in cage to the high 80's low 90's (92 max) during the day and for the 1st 3 days don't let it drop at night.  After that, if he seems better let it drop by maybe 10 degrees tops at night.  Keep the daytime temp in the upper 80's for at least 2 weeks. He should be eating after a week if this works, if not, then vet care is the only way to save him.  Ask the RSPCA if they would dispense the medication so that you could treat him.  I can get you the doses if they agree.  The trade name of the drug is Baytril (in the U.S.) and you'd need a very small amount.  It is very easy to give the shots.