CRF kitties vs CRH humans

so- I have 3 oldster civvies that are dx CRF...also have Gramma that lost use of kidneys after recent surgery for Aortic Anuerysm and is taking dialyisis in hopital. They have dx Gramma CRF.

The Gramma retains MASSIVE water weight if she doesn't take dialysis.

The kitties pee grapefruit size pee balls several times a day.

Why do CRF kitties pee and not take on water, but CRF Gramma takes on water and does not make pee?

Thank you.

 

It's the difference between kidneys that aren't working efficiently (peeing a lot) and kidneys that aren't really working (can't make pee) :-( Kitties that need dialysis -- kitties whose kidneys aren't working at all -- are usually euthanized rather than dialyzed.