My pet pinky rat keeps breathing hard

At five inches long he sounds older than a true pinkie. In proper lingo, a pinkie refers to a newborn rodent who has yet to grow hair. Newborns are almost impossible to hand raise. I've only known of a couple of folks who did it successfully, and they had tons of experience with rats. I think that's why everyone's so pessimistic. If your little albino has hair, has been in a snake cage for two weeks, and is five inches long, he might even be old enough to survive with urgent proper care and a strong will to survive. I agree with Elliriyanna that he may even be two or three months old. Still a juvenile, but old enough to be weaned and independent of his mother.

Good for you for caring enough to want to do something. Your baby's chances don't sound good, though. Odds are the stress and other things has caused your rescue to contract a respiratory infection at the very least. Rats are prone to them even without the horrific treatment this poor little dude has endured until now. If it was in a snake cage for two weeks without food of its own, no matter what its age I'm shocked it's still breathing. He's weak from starvation and illness. Try offering it baby food, or other pureed fruits/cooked veggies (no citrus). Get some flavored Ensure type drink and try syringe feeding it to get some liquid and calories into it. You can get tiny feeding syringes for kittens, or pick some up from a vet. They'll be about half the circumference of a golf pencil.

Keep it in a warm place, but not too hot. Try putting a heat pad on low underneath one side of the bottom of a small cage. The heat will radiate through the bottom and keep it warm. Leave half of the cage bottom non-heated, so if it gets too hot it can move away.

You can use flannel teeshirts or sweat pants as bedding for right now. Or even undyed household paper products like paper towels. Proper purchased bedding would be aspen wood shavings. Avoid (like the plague) pine or ceder as those give off phenols that will further damage his lungs. I'm assuming you're in the U.S.? Unscented Carefresh will also work, as will unscented Yesterday's News.

If it is still alive today, it will absolutely require a trip to a vet ASAP who specializes in exotics or rat care, and will need to be on antibiotics. The vet can evaluate it to see what else is going on or even if this baby is salvageable. If you can't afford a visit, explain your situation and ask what your options are. If you can get a weight on it--a digital kitchen scale that measures in grams is what you need. Then they may be willing to just charge you for the cost of the antibiotics.

If nothing else, they may be able to humanely euthanize your little trooper if he's too far gone.

(I hope someone who knows more than I do will reply too?)