Our oldest dog Emma (almost 12) is panting and drooling constantly, and now will barely use her back legs.  Doesn't whine when I put pressure on any areas, but is definitely distressed.   
Only change over the last week was that they got out and ran the woods/neighborhood for several hours on Wednesday.  She was visually sore yesterday, but nothing like this.     
Any suggestions, and are Medvet and OSU my only options?