About 5 months ago our cat started peeing on our shoes. Usually ones in the same spot.
A quick Google search determined it was stress; although I take Dr. Google with a grain of salt, so I took our quirky and fun little girl (4 years old) to the vet and after going on a few changes in the household:
- moved her litter box
- introduced a baby into the house
- generally peed after the baby would cry/fuss
The vet quickly agreed it was stress. We added another litterbox where she was peeing on our shoes, and changed her food to a stress reducing food. And increased play time.
Now she's back to her old self.
I'm no vet, nor do I know the situation exactly, but for us it was stress.
Although the diabetes posts seem to make sense too.
Regardless, go see a vet. They're the best people to talk to about this, they're literally experts