I have heard of this happening on the 2nd series of shots, I cannot remember who it was on here that it happened to!?
Hopefully they will have some answers for you on what they did. I know they went to an early appt. just in case there was a reaction and gave some benedryl beforehand. Do you know what the puppy got (what brand) of vaccines the first time? Did you go to the same vet or was it at the breeders? There are many diff. brands of vaccines and no two are the same.