If your vet suspects that your cat has CKD, s/he will usually run some
tests to confirm the diagnosis.
The various test results will also tell you and your vet where any
imbalances exist, which will help you to decide on the best treatments.
This page gives an overview of the various tests (which are covered in
more detail elsewhere on the site) and explains which are the most
important and how often these tests should be run.
The tests will give you some idea how severe your cat's case is, but
they are not the whole story - treat the cat, not the numbers.
Types of Test
There are a
number of different tests available. I know tests can be stressful both for your cat and
your wallet, but they are invaluable in deciding how to treat your cat
most effectively. Not every problem is apparent from the cat's behaviour.
Once you know what problems your cat is experiencing, you and your vet can
tailor the treatments to meet his or her needs.
Most vets who
suspect CKD will run tests on your cat's blood, but they may also run
They should do
a blood pressure check but unfortunately few vets seem to suggest this.
your vet may suggest an ultrasound, for example if s/he suspects that your
cat has kidney stones, or a kidney infection, or cancer.
Which Tests to Have
Initially some vets only test
a measure of kidney function called blood urea nitrogen (BUN) or urea,
or possibly BUN together with another test of kidney function called creatinine.
However, if you get to choose which tests are run, I recommend that you
ask for the following tests to be run as a minimum:
These days your
vet should be able to run most of these tests in-house and have results
within a couple of hours, which can be helpful if your cat is very sick.
However, it is
unlikely that they will be able to perform some of the more specialised
tests, and their machines may not be calibrated as frequently as in a
professional laboratory. See
Factors that Affect Test Results
for more on this.
I do have most
of my cats' tests performed in-house though, mainly because it is faster.
I think if you always have them run on the same machine, this is probably
This is the
most common type of test run on CKD cats.
This group of checks examines kidney function. It also looks for any
other abnormalities associated with poorly functioning kidneys such as
electrolyte imbalances, metabolic acidosis and phosphorus/calcium
imbalances. It usually includes other tests such as albumin, glucose and
cholesterol. There is more detailed information about all these tests
Many CKD cats
have high blood pressure (hypertension) which can cause blindness among
other problems, so it is really important to check for this. There is a
page devoted to
hypertension, which is diagnosed via a blood pressure monitor.
If your vet does not check your CKD cat's blood pressure, ask for it to
I am quite surprised how many vets seem to diagnose CKD at one visit, then
say they do not need to see the cat again for 3-6 months. This may be
possible for cats with very early CKD and few abnormalities in their test
results. However, in most cases I think your cat will probably need to
visit the vet pretty frequently, until any imbalances are under control
and your cat is stable.
You should then be able to reduce the frequency of your visits, though of
course you should always go to the vet if your cat seems sick or in pain.
balance the need to run tests in order to monitor and control disease
progression with the need to not increase your cat's stress levels
unnecessarily, and bear in mind that taking blood too frequently can
Your vet will
probably want to monitor your cat's kidneys values. It is also important
to monitor the following:
You may not
necessarily need to see the vet every week, how often will depend upon
which issues you are dealing with. If you are trying to control a
particular problem, it is
reasonable to test these every couple of weeks until you have got things
under control. Some tests, such as checking blood pressure, can be
performed by a vet tech or vet nurse, which should be cheaper.
Once your cat
seems stable, I would recommend checking bloodwork, urine and blood
pressure at the vet as follows:
If your cat's creatinine level is in IRIS Stage 2 or above
(creatinine above 1.6 mg/dl USA, 140 µmol/L international), I would ask for
tests every 1-3 months. All the above tests (under 1-8 weeks) should be
performed as appropriate, along with dental checks.
Six months is
the maximum length of time I would go between vet visits (personally I
would feel more comfortable with three monthly visits as a maximum), but
this may be appropriate for cats in early stage CKD (creatinine below
1.6 mg/dl USA, 140 µmol/L international) who are stable.
All the above tests (under 1-8 weeks) should be performed, along with
ISFM consensus guidelines on the diagnosis and
management of feline chronic kidney disease (2016) Sparkes AH,
Caney S, Chalhoub S, Elliott J, Finch N, Gajanayake I, Langston C,
Lefebvre H, White J & Quimby J Journal of Feline Medicine & Surgery18(3) pp219-239 states Following diagnosis (and stabilisation, if
necessary), initial re-evaluations should typically be undertaken every 1-4
weeks, according to clinical needs. Full monitoring will not be necessary at
each visit (and not all evaluations are needed in all cats and at all times),
but should be performed sufficiently frequently to allow good patient
management. Even in cases of early and apparently stable CKD, initial monthly
revisits can be helpful in supporting the diagnosis, providing support to the
owner, and in monitoring progression and therapy. In the long term, even if
stable, cats should be re-evaluated at least every 3-6 months. Particular
attention should be paid to appropriate monitoring of the efficacy of
interventions to ensure that therapeutic targets are being met. In advanced
disease, care may be needed to avoid exacerbating anaemia by too frequent blood
cases, do your own checks at home, e.g. regular weighing, monitoring of
food intake. if your cat seems to be deteriorating or you have any
concerns, you should seek your vet's advice regardless of whether tests
Thomas was tested
every week initially until his severe anaemia and high phosphorus levels were
under control. We then switched to three monthly, but as the disease progressed
we switched to every 1-2 months, then more frequently again as he worsened. In
retrospect, I think we should not have switched to three monthly, bearing in
mind how high his kidney values were at diagnosis.
If Your Cat Fights Blood Draws
Many cats find
having blood taken very stressful. There are some ways to minimise this
Stay with your
cat whilst the blood is drawn. Many vets like to take the cat "out the
back" to draw blood but this may frighten the cat, whereas a familiar face
(yours) can help keep the cat calm.
has a couple of videos about examining the cat with their guardian
present and tips on examining a fearful cat. However, as
Vetstreet explains, some cats may be
calmer away from their owner.
For cats who
fight blood draws like our Harpsie, it can be easier to take the blood
from a hind leg rather than from the jugular vein in the neck. Our vet
used to place a towel over Harpsie's head and draw blood from the leg. You
would probably expect a towel over the head to make a cat freak out more
but many cats find it calming. Taking blood this way takes longer than
taking it from the jugular but overall it still worked better for Harpsie.
Cats hate the
smell of alcohol, so it is better not to dampen down their fur with
alcohol before a blood draw because it increases their stress levels. It
is unnecessary anyway
unless your cat has a particularly weak immune system, e.g. s/he also has
Critical Care DVM
says "It is not necessary to “sterilize” the skin with alcohol prior to
inserting the needle. In reality, wiping a little alcohol on the skin does not
sterilize it, and the odor and feel of alcohol may aggravate your pet."
Not every vet routinely offers copies of test results to clients, but if
yours doesn't, ask for them. They will probably be meaningless
gobbledegook to you at first but don't worry, you will soon learn which
are the important readings and what they mean.
Keep your own records of your cat's symptoms and bloodwork results, so
you can monitor trends and have records you can take with you if you
have to take your cat to the ER or to see a specialist. See
Your Vet for more information.