calcium oxalate bladder stones

Question
My three year old Maltese male has had two surgeries to remove calcium oxalate stones from his bladder.  After the first incidence I moved him to hill's u/d dry food.  After the second I tried canned but his weight ballooned.  I went back to the dry version and serve it up like a soup in warm water.  He likes it well enough,  he is urinating frequently but given his history and age, I fear another occurrence is in the cards.  I had read that feeding raw white potatoes can increase the volume and alkalinity of the urine and decrease the likelihood of another occurrence of stones.  Is there any truth to this?  Thanks for your considered reply.  

Answer
Hi Philip!  
I am so sorry your Maltese is going through this at such a young age!  Some dogs are prone to stones, whereas others will never get them, even in old age.
I would try Science Diet C/D food.  I have seen this work better than the U/D. Calcium Oxalate Crystals are in your dog's urine, which these then stick together, forming stones.  Hill's Science Diet C/D food breaks down these crystals, which will result in the inability for them to create stones.
I have heard of potatoes working...but I have never actually witnessed a case that I had seen it done.  I would definitely try it.  It wouldn't hurt anything.
As for now, I would definitely suggest Hill's Science Diet C/D formula and monthly urinalysis testing to keep tract of how many crystals are in the urine.  This way the problem may be able to be stopped before another surgery is needed.
I hope this helps and please keep me posted!
Hilary