calcium oxalate bladder stones-preventive measures

Question
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Followup To
Question -
Doctor

Our 14-yr.-old all-american had surgery to remove bladder stones of calcium oxalate. We were told to look into a diet that can reduce the chance of recurrence. Apparently that should be low protein/low salt. Vet' wasn't very helpful except
to 'check Waltham's or Hill's'. Looked around online and can't seem to find what dog food
is low protein & low salt yet good for his main meal. Can you please give us your advice on this type diet and where we might order some? Thank you very much. (PS/He's doing great and only a few days since the surgery).
Answer -
Canned food is preferred since you want to increase water consumption to keep the bladder flushed out.  Low protein diets such as Hill's K/D or Purina NF can be used.  You could also feed a vegetarian formula.  You also want to discontinue any Vitamin C, D or Calcium supplements or those that acidify the urine as calcium oxalates will form in acidic urine.  Vitamin B 6 has been shown to reduce oxalate formation as well as potassium.   You can supplement B 6 but I would recommend her getting the potassium from fruits and veggies by addning those to the diet.  

Also, eliminate table food and treats,especially those items that are salty as this will lead to more calcium excretion.  You can get vegetarian treats or just give the fruits and veggies for treats.

Was her blood calcium level elevated?  Ask the vet.  If it is, then stones are VERY LIKELY TO RECUR.  Hyperparathyroidism can cause stones...an ionized calcium and PTH level should be checked.

GOOD LUCK!
Dr. Fry

Thank you!  Yes, apparently the calcium level was somewhat high. One of several vets (the rest didn't get into nutirtion much) said Waltham's S/O canine urinary would be good. We also saw one called Hi-Tor Neo-diet at our pet store which is low protein low salt; hoping that's ok because much cheaper and easier to get than Waltham's. Do you think it's ok? It has min crude protein 3.5% and min calcium .10%; he'd get 1 1/2- 2 cans/day.
I read online at the site marvistavet.com (calcium oxalate stones section) that potassium citrate is a good supplement to help prevent this kind of stones. I can get that from my own supplement source but need to know the mg/day for 60 lb. 14 yr.-old male and if it's given as one time/day.
Do you happen to know? (Hyperparathyroidism hasn't been mentioned, but I'll ask if it will be checked/considered). Thank you so much! Very much appreciate any input as to those above questions.

Answer
I would try the diet first before adding any potassium citrate supplements.  You can compare Waltham's S/O diet label to the others to see if they are similar....as I am not familiar with any of those diets.  Often times the diet alone will be enough to maintain a normal urine.  I would transition him to the new diet over the next week, then in about 2-3 weeks have another urine sample checked to see what his pH is as well as look for any crystals.  If the pH is acidic or he still has crystals, then you can ask your vet about supplementing with potassium citrate.  Ideally you want the pH of his urine to be 7.0, which is neutral.