My Luna had struvite crystals in her urine, which had led to a bladder infection and which can cause struvite stones if they remain untreated.

Struvite crystals develope when there's an alcalic pH-value in the bladder. A cat that once had struvite crystals will probably need a special diet for the rest of its life.

When a cat refuses to use its litter box, it could be for many different reasons, but you have to get the urine tested to find of there's a medical problem or not.

I think it could be very well that Patches is "only" getting into heat. When my Katz was 9 months old, she started peeing in one corner of the room, and when I got her spayed, she immediately stopped doing this. But you have to find out if it's heath related or not.

Kirsten