Our female socialized feral had a bladder stone a couple of years ago. It was suggested that it be removed surgically, but we worried that she may not have survived all the handling by strangers and the medications involved with surgerical procedures. She is a feral (not a stray gone wild), and ferals are very high stress creatures and some cannot stand being amongst humans they don't know and being handled by them. I had a friend tell me of a drug she used on herself for stones and how it worked so I started hunting it up online in relation to cats and I found a pharmicudical company in Virgin that made it for cats and sent it to me and yes it worked. The drug is called Chaca Piedrea. Look it up online there is lots written about it, make sure you are reading the articles pertaining to cats/dogs/animals - I hope you find the same success we did.
My 14 yr old male neutered cat developed bladder stones that were not diagnosed until he wasn't able to pee. We rushed him to the vet on Easter morning to have his bladder flushed out but during the procedure his bladder burst. $1,300. later he is doing well and is on a special diet. I feel if I had taken him in sooner the stones would not have irritated the lining of the bladder to the point of bursting. I would call your vet and schedule an appointment as soon as possible. Good luck, mamashu