CAT HEALTH SLIDE!
A good friend has a cat with what sounds like the same urinary problems. I looked up foods that cats can eat (and mine liked) that acidify the cat’s urinary system to prevent/cure urinary problems. From my searching:
...natural urinary acidifiers, including asparagus, peas, brown rice, oats, lentils, garbanzos, corn, Brussels sprouts, lamb’s quarters (the herb Chenopodium album, also known as pigweed), most nuts (except almonds and coconut), grains (not millet), and wheat gluten (used in kibble recipes). Once the pH is regulated, the urine pH should be checked at least twice a year. If a cat shows signs of pain or straining while using the litter box, immediate veterinary attention should be sought. It is important to not supplement the cat’s diet with urinary acidifiers unless it is actually needed because a too acidic pH can cause a different kind of stone to form (calcium oxalate stones).
On my first glance, my brain saw "brown rats".
No doubt, a key component to an active cat's healthy and well balanced diet.
(it's not just for breakfast any more)