Rockdoc
Sounds like soil contaminants ..... salt, alkali ... or worse. First I suggest you take a close up look at her feet to see if there are cracks in the pads ..... this can be caused by dry callouses and give the paw an opening to what ever it is in the soil. If cracks are apparent my treatment is any lanolin rich hand cream applied once or twice a day. After every walk I would wash her feet under a hose or in a bucket. If the ground is wet they may be using a weed killer or insecticide ...... but these days you never know what may be under the ground if it's land fill. My old Bouvi had cracks in his pads that were hard to heal and in winter road salt would really make him suffer ... the only solution was booties I got from Cabelas. These are also good as a temp measure while paws heal.
Al
