shuffling hind legs

Sun. Dec 20th - We gave Sam 1000 mL of fluids, one Prilosec, two magnesium tablets, two Sucralfate, two Prednisone & 12 Tramadol. Sam's hing legs seem a bit weaker today. We've noticed when he walks on the hardwood floors we can hear a slight shuffle. He isn't picking his paws up as much as normal. We don't think this weakness is like the calcium weakness we have seen before. We are worried about what could be causing it this change & hope it isn't nerve pain or issues from his lymph nodes.
It was another chilly day today but Mushka & Sam enjoyed some time outside and got a nice post bath bushing - lots o fur!