- This is usually one of the first questions people ask themselves after diagnosis.
- This page attempts to help you understand a bit more about what the test results mean, and why they do not tell the whole story.
- It also explains why it is not as bad as it sounds when your vet says your cat has lost a certain percentage of his/her kidney function.
Percentage of Function Lost
Let's get this out of the way first, because chances are things may not be as awful as you fear.
Most people panic if their vet says their cat has lost two thirds or more of his/her kidney function. I regularly hear from people who say things like "my vet told me my cat has lost 75% of kidney function so things look really hopeless".
Take a deep breath. I know it sounds like a massive loss of function, but it is actually completely normal for CKD not to be diagnosed until a cat has lost at least 66% of kidney function. In many cases the cat has lost even more kidney function. The What Happens in CKD? page explains why this is the case.
This may gradually change following the introduction in 2015 of the SDMA test), but even with this test, CKD cannot be detected until 40% of kidney function has been lost. So whichever way you look at it, your cat is unlikely to be diagnosed with CKD until a lot of kidney function is gone.
Some cats are diagnosed before they show any symptoms, perhaps because they have had annual blood tests run. If your cat has not been acting sick despite having lost 66% or more of his/her kidney function, this demonstrates that cats can often manage very well on limited kidney function.
On the homepage I give my vet's analogy of a CKD cat being near the edge of a precipice. Another way to look at it is that your cat was edging through a door and has now crossed the threshold; but the kidneys have probably only lost a tiny bit more of the function they had a few months ago when your cat was a step further away from the doorway.
It is also quite possible that your cat was fine one day and sick the next. In these cases, something may have happened to push the cat through the doorway, such as an infection. Treating the cause may allow you to pull the cat fully or partly back outside the door.
In either case, the cat might linger in the doorway, not moving fully into the other room for some considerable time. Many cats can continue to manage quite well even after diagnosis - for a small number of cats, things only become critical when they have lost as much as 90% of function, and there are some cats who cope astonishingly well with even less function.
So the goal is, not to worry about the function that has already been lost, but to try to help your cat manage with whatever function remains for as long as possible.