Originally Posted by mybubbles65
Am I being paranoid?
Sorry to hear about the loss of your kitty.
Unfortunately urinary tract issues, particularly crystal formation and blockages, are very common in cats these days, and most of the time it's because of what they're being fed. Dry food, in particular. So whatever cat you decide on, my number one suggestion would be to read this article and feed a wet food diet (even raw, if you feel up to it): http://www.catinfo.org/?link=urinarytracthealth
As for what age cat would be best for getting along with your dog, I'd suggest checking out some rescue organizations and seeing if they have an adult in a foster home situation where they already know whether s/he likes dogs or not. Doing proper introductions will also help: http://www.paws.org/introducing-cat-to-dog.html