Cats descend from desert hunters, and healthy feline kidneys are superb water-savers. They filter her blood, pull back everything worth keeping — water, potassium, B vitamins — and let out only a little concentrated urine.
Think of them as a fine filter. CKD turns that filter into a sieve.
As kidney tissue is lost, she can't concentrate her urine, so water pours straight through. She pees more — those bigger litter clumps — and drinks more to keep up. The empty water bowl isn't a sign she's fighting. It's a sign she's leaking.
And water isn't the only thing going down the sieve.
Potassium. CKD cats commonly lose too much potassium in their urine. Low potassium shows up as muscle weakness, stiffness and a poor coat — and may push the kidney disease further.
B vitamins. They're water-soluble, so they wash out with the urine. They run her appetite, her energy, her nerves.
Every extra lap at the bowl means extra urine — and a little more of what keeps her strong, gone.
She's drinking more. And she's losing more because of it.