Hi Jeff, at the rates quoted, it is only very mildly a skin irritant and providing you dont exceed these rates should not cause any poblems to the dogs pads but never the less, it is a type of bleach so to be sure, I'd leave it a day before letting the dogs on it. Ive been using this for ages without any detrimental effect on my dogs. Please be careful with the concentrate and NEVER mix it with any other chemical especially ammonia as it then produces a toxic chemical called chloramine, now technically urine contains ammonia so thats why i say, if it is doe urine on the stones, leave it a day before letting the dogs on it.
regards, Lannerman.