I am sorry you are going through this. From what I understand, male and female dogs get bladderstones for different reasons. I only have experience from a female foster having stones, and she had 4 large ones, larger than marbles, the largest being about 1/2 the size of a chicken nugget.
She got surgery and they did not come back. I don't know what is going on with your poor baby. Maybe take him to yet another vet? I doubt he was able to form more full on stones within one month. I really hope you find out soon, poor baby.
