Is the dog in pain? Or what is the benadryl suppose to help with?
My dog recently cut the meat in the webbing between the black pads with what I speculate to be glass too. It was a deep cut, got swollen for a few days and had pus, I still took her swimming, and she's recovering fine. She still runs like a nut and didn't really enjoy me touching it the first few days and now she doesn't mind anymore as it's healing ok on its own. The only thing I did is clean it and put iodine.