Oh how awful! I can't help for suggestions but I know that after the surgury he NEEDS to eat very little purines and drink lots of water. Here is a list (from the DalmatiAn Club of America) of what foods are high and low in purines.
Quote Originally Posted by The DCA
Shift the stone-former to distilled water, only.
AVOID:
Foods HIGHEST in Purines
anchovies
brains
kidney, beef
game meats (venison, etc.)
gravies
herring (including roe)
liver (calf or beef)
mackerel
meat extracts
mussels
sardines
scallops
yeast

EAT
Foods LOWEST in Purines
cheese
eggs
fats
fish roe (including caviar)
fruits & fruit juices
Thedca.org/stones