
It certainly sounds as though your bitch has cystitis or some other UTI, which is unlikely to be connected with eating the dry food. I've had cystitis myself, and have never eaten kibble in my life! However it is very painful so a trip to the for medication would be a very sensible thing to do.
I don't know how much your poodle weighs, but I was told recently by my vet that a 20kg dog needs to have a litre of water a day. If wet food is eaten then less wil need to be drunk as liquid intake, but if dry food is fed then it'll all need to be drunk.