Thanks for the update Amberlee. Continued prayers for Storm and KAK are on the way! Poor thing, I know how bloody and painful that surgery looks (I assisted in this very surgery when I was working at Gilroy Vet)...so I can understand why Storm isn't wanting to go pee. Do you know if Storm was getting painkillers?
You're right Amberlee, subcutaneous fluids (or simply sub-Q) is what Storm will be getting for his dehydration. This will also make him go pee, so hopefully he'll start going instead of holding it in.
It will take some time to heal, but I'm confident that Storm will pull through.
Lots of love and **hugs**, purrs and licks from the Thrash household.