Bulldogs World

For the last 2 weeks either Deuce or Oliver have gotten hives.  It seems like almost every other day one of them gets lumpy.  Benadryl does not help so I have been giving prednisone and that seems to do the job...until they come back.  I have narrowed it down to something outside but I cannot figure out what it could be.  We have had some warmer days in the last few weeks so alot of the snow has melted.  I am starting to think perhaps it is the salt from outside but this isn't their first winters.  Maybe our village used a new brand of salt this year?  The hives seem to be concentrated on the lower half of their bodies, especially on their legs and under their necks....maybe it gets there from scratching?  The hives do not even travel up their sides and either of them have had any on their backs.  They have never both gotten hives on the same day it is always one or the other.  They go a few days hive free and then all of a sudden get them again.  I am debating just going to get a steroid shot for them to see if that gives their immune system a kick in the butt.  Does anyone have any thoughts or suggestions?  I am going insane here....ahhhhhh!!!!!