White calluses on my rats feet

Question
Hi,  This morning my daughter noticed that one of my boy's wasn't moving his feet normal.  Well actually he was dragging them behind him and he tried to scratch his head and couldn't get his foot all the way up.  I looked at both rats feet and noticed a big difference in the two.  The sick one has a number of white pimple looking things on his feet.  It doesn't look like bumblefoot (they aren't red) and they have plastic on the bottom of all three stories (they are in a ferret cage) but the sides have metal bars and they do climb them often.  
The bumps are small, white and raised.  He was fine yesterday running around and this morning he just is kind of laying like a blob (not like him at all, he is usually a spaz)  
The only vet in the area that treats rats is Banfield and I have not heard good things about them and the last time I brought a rat there they tried to do all these expensive, unnecessary tests and my rat was fine a few days later with my own treatment.  I have tried googleing everything but can't find anyone with a similar problem.
Please help!  Thank you so much!!

Answer
 What concerns me more than the pimples is the fact that he cannot move his feet.  Even when a rat is in pain, they will still walk around and move their feet as normal unless it is impossible for them to do so.  Is it possible that he fell from a high place in the cage and hurt himself?  He may have injured his feet or even his spine.  Is his tail moving, or does it drag as well?  With hind end paralysis the tail usually just drags along.

 I haven't seen white bumps like that on a rat's foot and I searched around as well for anything like it with no luck.  I agree that it probably isn't bumblefoot; usually those sores are red and opened.  It may be blisters from dragging his feet along, but I really am not certain.

 If you don't want to take him to the vet you can try leaving him for 24 hours and seeing if he gets any better.  If he is showing the same signs after that time or has gotten any worse you will definitely have to have him looked at, even if it is by a vet who doesn't know a lot about rats.  If he is dragging his hind end and cannot move his back legs he may have hurt his back and in this case euthanasia is the only option.  Hopefully he will get better on his own, it certainly does sound strange.  Please keep me updated on his condition, as I am interested in finding out what happens.  Good luck!