Glad to hear Mickey's doing well and his scar is healing up nicely!! Poor little guy is scared of the vet now, but at least he gave them a stool sample
Here are a couple of website that have info for you. The first one has some info on stones, and the second one is a chart that shows low, medium, and high oxalate foods. You should stick to the low oxalate category.
Half a juiced zucchini will be good for him because it's low oxalate and it's a natural diuretic. It's good for the urinary tract.
Thanks for the update, and yes, the Royal Canin SO is supposed to be for oxalate stones as well if they don't like the u/d.
Ooops, silly me... I forgot to post the two websites. Here they are:
http://b-naturals.com/Dec2002.php http://www.branwen.com/rowan/oxalate.htm