I have no personal experience with kidney disease in dogs, but I sometimes
get asked about it, so below I explain the IRIS staging system for CKD in
dogs and provide links to further information and support groups.
IRIS Staging System
When your dog is first diagnosed, you may immediatrely
wonder how serious it is. Many vets now take the test results and categorise them
according to the system provided by the
International Renal Interest Society. This divides
CKD into four stages; so if your vet tells you, for
example, that your dog is in Stage 2, s/he is probably referring to the
IRIS staging system.
The IRIS staging system begins by looking at the cat's
(creatinine is a measure of kidney function). Here are the four stages, together with my estimate of
the likely percentage of function lost at each stage:
Stage of Disease
Level of Kidney Function Lost
Creatinine below 1.4
Creatinine below 125
1.4 and 2.0
2.1 and 5.0
181 and 440
Creatinine over 5.0
Creatinine over 440
Obviously, not every dog with creatinine below 1.4 mg/dl
(US) or below 125 µmol/L (international) has CKD! The problem is that when measuring creatinine,
you cannot detect
CKD until at least 66% of function has been lost, because before that there
are usually no symptoms (see
Therefore for dogs in Stage 1 who do have CKD, bloodwork values are usually within
the normal range, and kidney problems would
only be suspected if an anatomical or functional
abnormality had been detected, or if the SDMA test result indicates a
problem (see immediately below).
Following the introduction of the
SDMA test, which is thought to be able
to detect CKD when only 40% of kidney function has been lost, IRIS guidelines
state the following:
Over 14 ug/dl
Over 25 ug/dl
Stage 2 but with a
low body condition score
Treat as if in Stage
Over 45 ug/dl
Stage 3 but with a low body condition score
Treat as if in Stage
In all cases, two readings in a stable dog (who is not
dehydrated - this can make the numbers look a lot higher than they really
after fasting (though that is not always the best choice for a CKD patient), are required
before making a firm diagnosis of CKD. In practice, most vets will make
the diagnosis based on bloodwork taken once during your initial visit.
dogs only have tiny amounts of protein in their urine because their
kidneys do not allow the protein to leak through. In CKD dogs, this
mechanism can be faulty and excess levels of protein in the urine, known
as proteinuria but sometimes referred to as
microalbuminuria, may occur.
The usual way to determine if a dog has proteinuria is via
the urine protein:creatinine ratio (UPC).
Three urine samples should be collected over a mimimum period of two weeks
before a conclusion is drawn.
However, don't panic if your dog's level is over 0.4 because the UPC
ratio is not always accurate - for example,
blood in the urine, infection or
inflammation may give a false positive result.
Hypertension may worsen proteinuria, so getting blood pressure under control may lead to an
improvement in the UPC ratio. Even if your dog's UPC ratio is indeed high, it
may gradually reduce with
TREATING YOUR CAT WITHOUT VETERINARY ADVICE CAN BE
tried very hard to ensure that the information provided in this website is
accurate, but I am NOT a vet, just an ordinary person who has lived
through CKD with three cats. This website is for educational purposes
only, and is not intended to be used to diagnose or treat any cat. Before
trying any of the treatments described herein, you MUST consult a
qualified veterinarian and obtain professional advice on the correct
regimen for your cat and his or her particular requirements; and you
should only use any treatments described here with the full knowledge and
approval of your vet. No responsibility can be accepted.
If your cat
appears to be in pain or distress, do not waste time on the internet,
contact your vet immediately.
This site was
created using Microsoft software, and therefore it is best viewed in
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browsers, but I'm not an IT expert so I'm afraid I don't know how to
change that. I would love it to display perfectly everywhere, but my focus
is on making the information available. When I get time, I'll try to
improve how it displays in other browsers.
You may print
out one copy of each section of this site for your own information and/or
one copy to give to your vet, but this site may not otherwise be
reproduced or reprinted, on the internet or elsewhere, without the
permission of the site owner, who can be contacted via the
This site is a labour of love on my part. Please do not steal from me by taking credit for my work.
If you wish to
link to this site, please feel free to do so. Please make it clear that
this is a link and not your own work. I would appreciate being informed of