My Pet Rat

I have had my 2 pet rats for about 2 months now and one of them has started to make a croaking sound when he's breathing and he's also very skinny. where as my other ones fine. what could be the problem? i have had no money for a vet as i am unemployee. is there anyway i can fix it?

[Savas]

It would help if you let us know what type of rat it is. It does sound like a respitory infection, though. Certain types of rats do have a high incidence of tumour/cancerous growth. I hope this isn't the case with your little one.