What is wrong with my rat?
Yes rats can get respiratory infections multiple times and possibly will. The symptoms your are describing are basically text book secondary infection indicators which will need treating with a vet prescribed medication. Secondary infections, if not treated, can cause lung scaring and eventually death. This is not a nice death as generally the lungs end up filled with fluid and the animal suffocates. Some rats may require medication for the rest of their lives to control Myco and the secondary infections. Here is a little more about Myco and the effects of http://www.prrr.org/ratcare/illness/myco… Rats do not get colds like us, they can get allergies to their environments and start sneezing but if it is this there will be no wheezing and the rat would not be displaying forms of fluffed up fur. Goodluck with your rat.
He could either have: Mycoplasma (Mycoplasmosis)is a disease that effects almost every rat, it is basically impossible to find rats that are not born with it. OR Rats can have Pneumonia & other breathing problems as well, Which aren’t necessarily connected to Mycoplasma. Take him to the vet. You can’t treat it by yourself!
Its is probably Mycoplasma, like the others said. It would not be your fault, they get it when they come from the birth canal. My rat just had 7 baby’s and all of them had it, and I had to take them to the vet( they all got better). You can treat it successfully, but it must have vet care… But if it is not this I would IMMEDIATELY separate the the rats so if it is respiratory it will not spread! I think you should take it to the vet. I hope your baby gets better! Good Luck!!!