Cat can't pee? Lay off the seafood.

After scouring the internet and finding hippie goofball "cures" for cats with urinary tract issues, I took Thunderball to the vet who said cats don't tolerate high "ash" or mineral levels in their food, explicitly calcium, phosphorus and magnesium. And the #1 offender is seafood as it is high in phosphorus. So no sneaking kitty a can of tuna or seafood-rich cat food if s/he is having troubles peeing.