[Bobby dog]

Hi scottNY:
Here’s some info I have on cystine stones that might be useful in finding a proper diet for your friends dog from the University of Minnesota Urolith Center Veterinary Medicine:
http://www.cvm.umn.edu/depts/minnesotaurolithcenter/prod/groups/cvm/@pub/@cvm/@urolith/documents/asset/cvm_asset_108327.pdf

Perhaps your friend could look into a custom Rx diet from Just Food for Dogs or Balance It:
http://justfoodfordogs.com/
https://secure.balanceit.com/