[Help] My dog has a blister under the paw

Found blood on my dogs bed and after a thorough search found she has an open blister under her paw. I washed it with soap and disinfected it with hydrogen peroxide (it was painful for her). She walks normal though and it doesnt seem to bother her much. Still worried it can get worse. How should I treat it due to the difficult spot? via /r/dogs http://ift.tt/2sjYKu7