bull mastiff with bladder stones

Question
I have a 3 year old bull mastiff with bladder stones and he just had his 2nd surgery to remove them and was castrated at this time.  For the past year he has been on Royal Canin Urinary food.  It is expensive and we still had to have surgery.  Is there something else we should be feeding him? I feel that we should have had him castrated at the first surgery as the prostate was collecting the bacteria and causing the stones I feel.  The first surgery had the stones tested and they took so long to get the results back that we were confused as to what the cause was.  This time we have been faithful to not give him anything but the Royal Canin food.  We love our guy and he is so patient with us silly humans and never complains so we want to do right by him.  Can you suggest something we can feed him that is good for his condition and since what we think is the cause do we need to worry about his diet as much anymore?

Answer
Good morning, Beth-Anne.

I would certainly still be concerned about his diet.  Before recommending a diet, I would need to know what kind of stones were forming and if he has or has had any other health issues.  

As well, if you know what his urinary PH is and was, that would be helpful.

Typically, stones will form if the urine is to acidic or too alkaline - these issues can be controlled with diet.  At the same time, there are other types of stones that can form that would require special consideration.  

Please let me know what kind of stones he had and we will proceed from there.

Sincerely,
Gail E. Vigneault