I feel your pain Ginsue. Last summer one of our guys (we have 4) was acting punky and totally unlike himself, isolating himself and yowling. The wife noticed he had a really tight stomach and was just miserable. Now naturally this was on a Saturday afternoon which mean the only vet open was the Emergency clinic. I am at work so the Mrs carts him off to the ER.
Blocked urinary tract due to bladder stones-they had to do emergency surgery to remove them to the tune of 1400.00.
Ouch! Seems like too much to spend on a cat but what kind of a price do you put on a family member?

You are on the money as far as diet. Dry foods are generally a bad thing for a cat. There is too much ash and useless filler in them and it can cause problems with the poop tube system as well.