My aunt's cat who was neutered at a young age had some sort of urinary stones problem, also at a pretty young age. He had to have very expensive surgery and the vet said, "Even though no one will tell you this and will deny this, I think that the standard neutering of neutering so young is what is causing more and more of these problems." I'm wondering if it is similar to urinary calculi in goats- you wait until they are more mature before wethering to prevent it.
We neutered our male GSD, but waited until he was a year.
My Schnorkie is not spayed and it is not a big, messy problem when she is in heat, despite what the vet told us it would be.