Sorry about the stone
You may want to put a little bit of Bragg's Apple Cider Vinegar in your doggy's water to help this from happening again. I had an adult dog(re homed to me with a pre existing problem from a terrible diet) that produced bladder stones and was able to keep him alive for an extra year by giving him ACV and raw honey mixed with water.
My yorkie has a tendency to have tears which run down the fur like stains. The ACV also helps with that bringing the ph into balance. So when I fill up the water dish(1/2 c)of water I add 1/4-1/2 tsp of ACV to the water to help with tears and keep the ph balanced in the body.
ACV is natural and with raw honey(which is a natural antibiotic) it will dissolve stones helping them to pass. Also diet is very important. A raw diet should help.