Dr. Kris, what is your opinion of, upon diagnosing a cat in renal failure, "flushing" the kidneys with large amounts of subQ fluids for 2 or 3 days?

Thank you, Casey.

It’s tempting to think that when we give fluids, we are “flushing” them (kind of like an oil change - change the oil and filter, so we run smoother).

You might hear a vet talk about flushing the kidneys because people sometimes just want to know the basic minimum in a way they can understand - especially if they are overwhelmed or bombarded by test results.

So someone says flushing, but what they really mean is restoration of electrolyte, acid/base and hydration status.

But I take your meaning - here we are talking about using "large" amounts of fluids to “flush out” the renal toxins.

I can have a patient with CKD come into the hospital, looking bad. Test their numbers.

I can then give them IV fluids for several days, and watch them get better and better, so they begin to eat and look alive. They go home happy cats.

So, the fluids didn’t flush out anything.

What the fluids did was correct for dehydration, acid / base balance, restore or correct electrolytes, and helped to manage phosphorous.

And I'm also not discouraged, because how I place value on bloodwork measurements:


So it was more of a correction vs a flush, in the way we think of flushing, right?

I don’t need large volumes to do this - only the right volumes calculated for that individual.

Now that scenario is for common presentations of CKD.

If i have a cat who comes in blocked (can’t pee - medical emergency), they can have sky high uremic toxins in the body. Like brutal levels. You can “flush” that out - you give the fluids, and those can be eliminated by the body. It works, because the problem was "post renal". It happened independent of a kidney issue.

Test this kitties blood the next day and wow - it’s like a miracle happened.

Then, there are cats who get into toxins. There is a case for “flushing” there - controlled diuresis.  But you are not being aggressive with the fluids - you need just enough to make them pee regularly, and to counteract the fact that they probably feel punky and won’t want to drink so much.

So all in all, never large amounts, just the right, calculated amounts (like I do here: www.iwillhelpyourcat.com/videos/#/sq-fluids-by-the-numbers-how-much-how-often/), designed for a purpose.


Dr. Kris