Canine Hyperuricosuria
I've posted a link to another thread where I taked about this genetic disorder, with reference to uric acid crystals. There is a great link in this thread to UC Davis, that you will want to follow.
They also talk about oxalate and struvite crystals. There if you go to the link I posted about treatment protocols they discuss this well.
Usually there is a diet plan to follow as well.
If you have problems with following the links let me know and I'll repost here.
It's always scarey when something new crops up.