I hear quite regularly from people who are worried that they could have
prevented their cat developing CKD but failed to do so.
In many cases, these people have just lost their cat and are overcome with
grief and guilt; in other cases their cat has just been diagnosed and they
too are feeling guilty.
Others have lost a cat and are now adopting a new cat, and are terrified
at the thought of having to go through CKD again in the future.
In most cases you cannot prevent CKD. However, there
are a few steps you can take to reduce the risks, which this page
Could I Have
I must say, we humans do have an amazing capacity to beat ourselves up.
People worry about everything they did or didn't do. Many focus in
particular on the foods they have been feeding, convinced that they made
Let me spell
this out loud and clear: it is highly unlikely that anything you did or
didn't do caused your cat to develop CKD. In truth, CKD is rarely
avoidable, particularly in older cats - as the
Happens in CKD page mentions, around 10% of cats over the age of ten will
develop CKD, with as many as 30% of cats over the age of 15 having the
disease. The Causes of CKD
page discusses the various causes in more detail.
On the one hand, this is
reassuring. On the other hand, it means, of course, that this page is
necessarily short, because it is not usually possible to prevent CKD.
We all know of people who eat healthily and exercise, only to drop dead at
the age of 40. We all also know of people who eat whatever they like,
smoke like chimneys, drink like a fish, and live to 98. It is the same
with cats. Many factors
determine a cat's fate, including luck. Some are dealt a better genetic
hand than others. Pedigree cats tend to have shorter lives because of
inbreeding; but if, like me, you like a particular breed, you may have to
accept that as one of the risks you take.
Which Steps to Take
Having said all that, there are a few things you can
do. These are
the steps I would take to reduce the risks of CKD developing; though
remember, there are no guarantees. Still, none of
these steps is particularly onerous, and you will note
the food suggestions are also not too gruesome - there is simply no evidence
that diet plays that big a role in the development of CKD.
Ideally you want to implement all these steps when your
cat is young. It is usually easier for cats to accept new routines when
they are young, and it increases your chances of success. Still,
implementing many of these even at a more advanced age can still be
beneficial, for example cleaning your older cat's teeth regularly.
Even if you
don't have your cat vaccinated every year, you should still have your cat
thoroughly checked over by your vet at regular intervals. See below for
frequency of visits and which checks and tests to run. Doing this will not necessarily
prevent CKD (though it may do so if, for example, you are able to nip a
urinary tract infection in the bud before it rises into the kidneys and
causes permanent damage), but it can help you detect it earlier
so you can be proactive with treatments. It also enables you to establish
a relationship with your vet.
visits, be sure to monitor
your cat at home for weight loss, food and water intake and changes in bladder or
bowel habits or in coat condition. I recommend weighing your cat regularly
(see scales) in
order to spot any weight loss early, which may indicate CKD or other
health problems such as
your cat seems ill between check ups, or you notice changes such as weight
loss or reduced appetite, you should take your cat to the vet.
All of my cats visit the vet for a check up at least once a year, no
matter how old they are. The check up includes
a physical examination and a dental check as a minimum. If the vet or I
have any additional concerns, urinalysis and blood tests may also be run.
If my cats are to undergo surgery for any reason, blood tests are run
Although occasionally younger cats get CKD, it tends to be a disease of
the older cat. I therefore make it a rule that any of my cats who are
aged between eight and ten have the following tests once a year:
Once cats reach the age of ten, I would recommend checks every
The American Association of Feline Practitioners
guidelines on how to be proactive in caring for a senior cat. It
recommends (page 3) that blood tests, urinalysis and a blood pressure
check should be performed every year in cats starting between the ages of 7 and 11
with no clinical signs of disease.
discusses the results of a study at a Los Angeles
veterinary hospital into the benefits of bloodwork and other tests
performed in cats over the age of 7 who were apparently healthy.
Starting young can be particularly beneficial if you
wish your cat to have health insurance, because you will have few or no
exclusions if your cat is young and healthy. Choose your insurer
carefully: you want one which provides cover for life, rather than one which
pays up the first year a problem arises but then excludes that problem
thereafter, or one who pulls or reduces the cover massively once the cat
reaches a certain age (which may be as young as eight).
If you don't insure your cat, it can be worth
self-insuring if you can. This basically means you put money aside to pay
for future vet bills. Some people believe this is better value than
Consider doing this at least once every twelve months in healthy 3-6 year
olds, in order to know their baseline measurements.
Check blood pressure at least once yearly in healthy 7-10 year olds.
Check blood pressure every 6-12 months in healthy geriatric cats (aged
Check at least every 3-6 months in cats with risk factors or signs of high
It is important
to monitor your cat's weight. Weight loss in older cats is not good news.
Effect of diet and body composition on lifespan in
aging cats (2010) Cupp CJ and Kerr
WW Presentation to the2010 Nestle Purina Companion
Animal Nutrition Summit found that "aging cats that lose excess body weight and body condition (fat or
lean) have a significantly greater risk for earlier mortality." Therefore
I would not put your older cat on a diet. If your cat is getting thin, try
to get weight on. Low protein foods are not a good idea for healthy cats
Determining protein requirements: nitrogen balance
versus lean body mass (2013)
Laflamme DP Nestlé Purina Companion Animal Nutrition Summit Tackling
Myths About Pet Nutrition pp42-45 states "Previous research suggests
that unexplained weight loss, especially in geriatric cats, can be the
first sign of an impending terminal condition."
Effect of nutritional interventions on longevity in
senior cats (2007) Cupp CJ, Jean-Philippe C, Kerr WW, Patil AR &
Perez-Camargo G The International Journal of Applied Research in
Veterinary Medicine5(3) says "there is evidence that extreme
leanness in old cats may actually be detrimental. Emaciated cats had a
significantly higher risk of death compared with cats in optimal body
condition. Perez-Camargo et al demonstrated that body weight, lean body
mass, and fat mass decline in cats over the age of 12 years, particularly
in the last 1 to 2 years of life."
Skinny old cats: why some senior cats lose weight. What's going
(2014) Williams D
states that the last study mentioned above found that "a control
diet (nutritionally complete and balanced adult cat food) supplemented
with antioxidants (vitamin E and β-carotene), a blend of n-3 and n-6 fatty
acids, and a prebiotic (dried chicory root) was associated with reduced
decline in body weight and increased longevity (by more than 1 year)
compared with feeding either the control diet alone or the control diet
supplemented with antioxidants alone. These striking observations
illustrate the potential benefit to be gained from dietary and other
interventions to address the gastrointestinal changes that appear to be so
common in aging cats."
Since cats are unique physiologically, there is a whole
host of items which they should avoid. Antifreeze and
lilies can kill a cat. There is more information
here. I never
allow lilies in my home for this reason, they go straight in the bin
should anybody happen to bring me any.
Most non-steroidal anti-inflammatory medications are a problem for cats,
who can only metabolise them very slowly. In some cases, kidney damage may
result. If your otherwise healthy cat needs to use meloxicam (Metacam) for
some reason, the dosage used is crucial. Please see
Treatments for more information.
A surprising number of foods are bad for cats. Grapes
and raisins may damage the kidneys. Garlic and onion can cause anaemia.
Fish can be a problem if you feed nothing else, even if you are feeding a
commercial fish-based food.
The Merck Veterinary Manual states that
"there are reports of
commercial cat food causing severe neurologic disturbances in cats fed an
exclusive tuna diet for 7-11 months."
has a list of foods to avoid.
Infections and Inflammation
Treat infections promptly, particularly urinary tract
infections, which may rise into the kidneys and cause permanent damage.
Take particular care of your cat's oral health. Most
cats develop dental problems by a young age, 3 or 4.
The Cat Doctors
state that "Dental disease doesn’t affect just the mouth. It can
lead to more serious health problems including heart, lung and kidney
for more information on this.
Learn how to use a feline toothbrush and clean your
cat's teeth regularly.
If a dental procedure nevertheless becomes
necessary, have it performed promptly.
See Dental Problems
for more information on feline toothbrushes and precautions during dental
I am in two minds about vaccinations. If you have ever had
a cat develop cat flu (feline herpes virus), as I have, you know it is
worth avoiding, and vaccinations can help with this. On the other hand,
there is some indication that there may be a link between vaccination and
If you are in the USA, the protocol is that the
standard vaccinations now only need to be given every three years, which
provides adequate protection but may reduce the risks. The frequency for
rabies varies, depending upon the vaccine used.
For what it is worth, I do vaccinate my own cats if
they are healthy, at
least until they are twelve years old.
Diet is a
tricky area, because feline nutritional needs are complex. Although some people
have strong opinions about which are the best foods for cats,
unfortunately, there is no firm evidence in many areas.
Many people are evangelical about this. Some
of them go so far as to claim that feeding dry food only may actually
cause CKD, although there is no evidence of this.
I certainly am not opposed to feeding wet
food, but unfortunately it is not always as ideal or simple as it first appears - see
Foods to Feed for more information.
A possible compromise is to do as I do and feed a mixture of wet and dry
Phosphorus is a problem for CKD cats
because their kidneys cannot excrete it efficiently, so it builds up in
their bodies. Healthy cats should be able to excrete phosphorus, so in
principle there is no reason to feed a reduced phosphorus diet to healthy
cats. If you do, it is
possible that phosphorus levels might reduce too far (below 3mg/dl in US values in bloodwork), which can cause weakness and lethargy.
Personally, I would not be at all
concerned about the phosphorus levels in a food for a younger cat -
kittens in particular, who are still growing, need phosphorus in order to
build healthy bones.
Having said that, since CKD cannot be
detected until at least 66% of kidney function is already gone (though the
test may change this), it may be worth considering feeding lower
phosphorus foods to an older cat (over ten years of age). Discuss this
with your vet.
Therapeutic kidney diets tend to have a phosphorus level
of around 0.5-0.7% on a dry matter analysis basis. AAFCO regulationd
require that any commercial food in the USA
which is labelled as a complete adult maintenance diet will have a minimum
phosphorus level of 0.5% on a dry matter analysis basis. I would aim to
feed a food with a phosphorus level of 0.5-1.0% on a dry matter analysis
basis; but remember, the most important thing is that a cat eats. You can
check the phosphorus levels in various foods
The effect of moderate dietary protein and phosphate
restriction on calcium-phosphate homeostasis in healthy older cats
(2016) Geddes RF, Biourge V, Chang Y, Syme HM & Elliott J
Journal of Veterinary Internal Medicine30(5) pp1690–1702
looked at the effects of reduced protein and phosphorus intake in healthy
older cats (over the age of nine). The cats were fed 76 g/Mcal protein and
1.6 g/Mcal phosphorus while the cats in the control group were fed 86
g/Mcal protein and 2.6 g/Mcal phosphorus, in both cases monitored for 18
months. The study concludes "Feeding a moderately protein- and
phosphate-restricted diet has effects on calcium-phosphate homeostasis in
healthy older cats and is well tolerated. This might have an impact on
renal function and could be useful in early chronic kidney disease."
Effect of a high phosphorus diet on indicators of
renal health in cats (2018) Dobenecker B, Webel A, Reese S &
Kienzle E Journal of Feline Medicine and Surgery20(4)
pp339-343 fed thirteen healthy cats a diet containing around five times
the maintenance requirement for phosphorus for 29 days. The study found
that "Renal phosphorus excretion was significantly increased in the HP
group (115 mg/kg body weight/d vs 16 mg/kg body weight/d in the CON
group)." I would have thought this would be expected, since the excess
phosphorus has to be dealt with somehow; but having to process more
phosphorus than is necessary may place additional stress on the kidneys. The study concludes "The intake
of a diet with an excessive content of highly available phosphorus may
have adverse effects on parameters of kidney function in healthy cats."
Observation about phosphorus and protein supply in
cats and dogs prior to the diagnosis of chronic kidney disease
(2018) Böswald LF, Kienzle E & Dobenecker B Journal of Animal
Physiology and Animal Nutrition 102(Suppl 1) pp31-36 found that
many cat foods far exceed the mimimum level of phosphorus recommended by
AAFCO and concludes "The results of this retrospective study, despite its
limitations, hint at a link between a high, long-term P intake and renal
disease in cats. Further investigations and preferably the definition of a
safe upper limit for P are warranted."
Effects of the longterm feeding of diets enriched
with inorganic phosphorus on the adult feline kidney and phosphorus
metabolism (2018) Alexander J,
Stockman J, Atwal J, Butterwick R, Colyer A, Elliott D, Gilham M, Morris
P, Staunton R, Renfrew H, Elliott J & Watson P British Journal of
Nutrition21 pp1-21 looked at varying levels of phosphorus and
calcium intake in cats. In the first part of the study, diets providing
1·2 or 4·8 g/1000 kcal of phosphorus (which is approximately 3·6 g/1000
kcal inorganic phosphorus), and a calcium:phosphorus ratio of 1:2 and 0:6
respectively were fed. The study was halted prematurely because after four
weeks GFR had reduced and changes in the cats' kidneys were also visible
on ultrasound. The study states "We conclude that the no observed adverse
effects level for total dietary P in adult cats is lower than 3·6 g/1000
kcal (4184 kJ), however the effect of inorganic P sources and Ca:P require
Evaluating phosphorus, calcium and magnesium content
in commercial cat foods (2020) Summers SC, Stockman J, Larsen
JA, Zhang L & Rodriguez AS Journal of Veterinary Internal Medicine34(1) pp 266-273 states "High P containing foods might be involved
in the etiology of CKD in cats considering that CKD cats have
significantly higher P and protein intakes before diagnosis compared to
age-matched control cats without CKD."
A new phosphorus binder for cats called Lenziaren (also known as SBR759)
was introduced in Japan and Taiwan since 2013 and presumably Novartis, the
manufacturer, will be releasing it in other markets in due course.
free feeding with Factor-2 (a composite variable composed of fiber,
magnesium, protein, sodium and ash);
and fibre alone.
concluded that free feeding was associated with increased odds of
developing CKD. However, they did not simply free feed the cats; they also
gave them additives. It is therefore not known whether free feeding alone
would give similar results.
I myself have always free fed, and will continue to do so. In the wild,
cats naturally feed multiple times a day. See
Nutritional Requirements for more information on this topic.
High Quality Foods
This is another
hot potato. Many people appear to be obsessed with feeding high quality
foods, particularly high quality protein. What is high quality protein for
a CKD cat does not mean what you probably think it means (see
What is high
quality food for a healthy cat is debatable. Many people buy "premium",
"high grade" foods, but what does that mean exactly? Why do so many of
this type of food contain fruits and vegetables which cats do not need?
Many people hate corn in foods, yet corn gluten meal is actually a protein
that is almost as bioavailable to cats as chicken.
Please read the
page for more information on a cat's physiological needs and
Which Foods to Feed
for more information on commercial foods. Although these pages are geared
towards a CKD cat, they do contain some information on feline nutritional
What Not to Feed
I hear from people who have
recently lost a cat and who want to try to ensure their remaining cats do
not develop CKD. They have heard that a reduced protein intake may help CKD cats, so
they sometimes are considering feeding therapeutic kidney diets to their
other cats in the hope
that feeding such foods may also prevent CKD.
I do not recommend this,
because not only it is not going to help, but may even may cause problems. Healthy cats have a requirement
for relatively high amounts of protein (see
In fact, it is commonly recommended that even cats who already have CKD
should not have protein restricted in the early stages of CKD.
I would therefore not recommend feeding a low protein diet to a non-CKD
cat, because it may eventually lead to malnutrition. In
Nutritional management of renal disease
(2008) Presentation to the World Small Animal Veterinary Association World
Congress Dr K Sturgess states "From studies performed in
dogs and cats, it can be concluded that there is no evidence in
these species to suggest feeding high protein diets to normal animals is
Excess Vitamin D
Cats cannot manufacture Vitamin D so
must obtain it from their food. However, many commercial foods seem to
contain levels in excess of current maximum US allowances (10,000 iu/kg for
Update on the etiology of tooth resorption in
domestic cats (2005) Reiter AM, Lewis JR & Okuda A
Veterinary Clinics Small Animal Practice35 pp913-942 states
"results of experimental studies on cats
fed diets high in vitamin D3 (15,000–33,840 IU/kg of dry matter) were
contradictory, ranging from no evidence of detrimental effects on feline
health to a high prevalence of renal dysfunction and mortality."
Vitamin D intoxication caused by ingestion of
commercial cat food in three kittens (2013) Wehner A, Katzenberger J, Groth A, Dorsch R, Koelle P,
Hartmann K, Weber K Journal of Feline Medicine & Surgery 15(8) reported on three kittens in Germany who became ill after eating a
commercial food containing too much Vitamin D. One recovered, one was put to
sleep, the third has ongoing kidney damage. The commercial food in question was Almo Nature
Kitten with Chicken food. It had a declared amount of Vitamin D3 of 6488
IU/kg (dry matter) but analysis showed that the food actually contained
202,155 IU/kg (dry matter).
It might be wise to feed a food that does not exceed the vitamin D
diets over the last ten years have been reformulated to promote "urinary
tract health", or words to that effect. Essentially, these diets are
acidified, so as to reduce the risk of cats developing
urinary tract disease (FLUTD). Cats with FLUTD tend to have urine that is too alkaline, and are therefore
at risk of developing struvite crystals, which develop in an alkaline
environment. Feeding an acidified diet reduces this risk.
Unfortunately, feeding these diets to cats who are not at risk of FLUTD may lead to urine that is too acidic.
It is speculated that acidified diets may be a factor in the increase in
calculi (kidney stones)
i.e. calcium oxalate stones, which develop in an overly acidic
which in turn are a risk factor for
developing CKD. These stones, unlike struvite,
cannot be dissolved by diet - they can only be removed by surgery.
may also contribute to low potassium levels (see below).
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
Internet Explorer. I know it doesn't always display too well in other
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. I am trying to teach myself to use
another type of software, in the hope that using it will enable the site to
display better in the future.
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 (though it is almost 1000 pages long, so it is
probably cheaper and it is definitely easier to buy the book version!), 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