24 July 2000 - 24 July 2020

Twenty years online!

(Not tax deductible since I am a private individual)








Feeling Overwhelmed? Let's Get Started

Is There Any Hope?

I Don't Know What the Test Results Mean or Which Are Important

So Just How Sick is My Cat?

Commonly Seen Symptoms

Commonly Used Treatments

Financing Treatments




Site Overview

Just Diagnosed? What You Need to Know First

Search This Site



What Happens in CKD

Causes of CKD

How Bad is It?

Is There Any Hope?

Acute Kidney Injury



Phosphorus Control


(High Blood Pressure)



Potassium Imbalances

Pyelonephritis (Kidney Infections) and Urinary Tract Infections NEW

Metabolic Acidosis

Kidney Stones



Nausea, Vomiting, Appetite Loss and Excess Stomach Acid

Maintaining Hydration

The B Vitamins (Including Methylcobalamin)




Ways of Assessing Food Content, Including What is Dry Matter Analysis

How to Use the Food Data Tables

USA Canned Food Data

USA Dry Food Data

USA Cat Food Brands: Helpfulness Ratings

USA Cat Food Brands: Contact Details

USA Food Data Book



Coping with CKD

Tanya's Support Group

Success Stories



Important: Crashing

Alphabetical List of Symptoms and Treatments

Fluid and Urinary  Imbalances (Dehydration, Overhydration and Urinary Issues)

Waste Product Regulation Imbalances (Vomiting, Appetite Loss, Excess Stomach Acid, Gastro-intestinal Problems, Mouth Ulcers Etc.)

Phosphorus and Calcium Imbalances

Miscellaneous Symptoms (Pain, Hiding Etc.)



Early Detection

Blood Chemistry: Kidney Function, Potassium, Other Tests (ALT, Amylase, (Cholesterol, Etc.)

Calcium, Phosphorus, Parathyroid Hormone (PTH) and Secondary Hyperparathyroidism

Complete Blood Count (CBC): Red and White Blood Cells: Anaemia and Infection

Urinalysis (Urine Tests)

Other Tests: Ultrasound, Biopsy, X-rays etc.

Renomegaly (Enlarged Kidneys)

Which Tests to Have and Frequency of Testing

Factors that Affect Test Results

Normal Ranges

International and US Measuring Systems



Which Treatments are Essential

Fluid and Urinary Issues (Fluid Retention, Infections, Incontinence, Proteinuria)

Waste Product Regulation (Mouth Ulcers, GI Bleeding, Antioxidants, Adsorbents, Azodyl, Astro's CRF Oil)

Phosphorus, Calcium and Secondary Hyperparathyroidism (Calcitriol)

Phosphorus Binders

Steroids, Stem Cell Transplants and Kidney Transplants

Antibiotics and Painkillers

Holistic Treatments (Including Slippery Elm Bark)

ESAs (Aranesp, Epogen etc.) for Severe Anaemia

General Health Issues in a CKD Cat: Fleas, Arthritis, Dementia, Vaccinations

Tips on Medicating Your Cat

Obtaining Supplies Cheaply in the UK, USA and Canada

Working with Your Vet and Recordkeeping



Nutritional Requirements of CKD Cats

The B Vitamins (Including Methylcobalamin)

What to Feed (and What to Avoid)

Persuading Your Cat to Eat

2007 Food Recall USA



Oral Fluids

Intravenous Fluids

Subcutaneous Fluids

Tips on Giving Subcutaneous Fluids

How to Give Subcutaneous Fluids with a Giving Set

How to Give Subcutaneous Fluids with a Syringe

Subcutaneous Fluids - Winning Your Vet's Support




Heart Problems



Polycystic Kidney Disease (PKD)


Dental Problems





USA Online

USA Local (Fluids)




The Final Hours

Other People's Losses

Coping with Your Loss




Feline CKD Research, Including Participation Opportunities

CKD Research in Other Species

Share This Site: A Notice for Your Vet's Bulletin Board or Your Local Pet Shop

Canine Kidney Disease

Other Illnesses (Cancer, Liver) and Behavioural Problems

Diese Webseite auf Deutsch



My Three CKD Cats: Tanya, Thomas and Ollie

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Home > What You Need to Know First




This page is a summary page. The goal is to explain:

  • what is CKD

  • the main test results

  • commonly seen symptoms of CKD

  • which treatments are commonly used

This page has links to more detailed information about each issue that is mentioned. However, I recommend that the first time you visit this page, you read it in its entirety without following any of the links, so as to obtain a general overview of what lies ahead.


Feeling Overwhelmed? Let's Get Started


You've just been told your cat has CKD and you are scared and frightened. So you found this site, and now, to add to your woes, you feel overwhelmed by all the information here. Clearly this is a complicated disease and you are not sure you can deal with it!


Well, take a deep breath because, honestly, it is not that bad. I had no scientific training at all when I first began dealing with CKD, in fact I was a linguist who was intimidated by scientific subjects, which I absolutely hated at school. But I did manage to learn about CKD, because it was essential if I was going to save Thomas's life; and you can do the same. Remember, knowledge is power! You need to be able to understand what is going on with your cat so you can obtain the most suitable treatments for him/her.


The primary goal when treating CKD is to help your cat feel better. Fortunately in most cases this is an achievable goal.


The secondary goal is to prolong life. This goal is secondary because there is not much point prolonging life if there is no quality to that life. However, since it is usually possible to help the cat feel better, obviously you want to then keep your cat with you as long as you can.


The good news is, you won't need to learn everything at once; and you certainly won't need to learn as much as I have. This site aims to cover every eventuality regarding CKD, because each cat presents with a different set of symptoms, so including them all helps new readers spot the issues that apply in their particular case; but you are highly unlikely to be faced with all the symptoms or need to use all the treatments.


Here are some possible scenarios:

  • Most people will be faced with two or three issues to start with. Virtually every CKD cat has a problem with not eating and may vomit, especially white foam. Virtually every CKD cat has high phosphorus levels, as shown in their blood tests.

  • Some CKD cats, especially those diagnosed with very high blood test values, will be dehydrated.

  • A small percentage of CKD cats will be anaemic. If your cat is eating litter or licking concrete, s/he is probably anaemic.

  • Some CKD cats will have hypertension (high blood pressure). If your cat has gone blind or is having seizures, s/he could well have hypertension.

Whatever problem you are facing, in most cases it will be treatable. Yes, CKD is scary at first, but given time you should find that it becomes a manageable part of your lives. Most people find they quickly get into a routine and only need to find maybe 10-20 minutes a day to help their cat, including time needed to give subcutaneous fluids at home if necessary.


If even this page looks too overwhelming, try the Key Issues page instead. This page talks about what the tests mean, what symptoms you might be seeing and which treatments help. The Key Issues page simply gives a short overview of the most important things to focus on to help your cat feel better and increase his/her chances of survival. After you've read it, you can always come back here for more detailed information or dip into the other pages of the site.


Is There Any Hope?


CKD is a progressive disease of the kidneys. This means the kidneys gradually get worse, sometimes in stages. In cases of CKD, the kidneys do not suddenly seize up and stop functioning, so it can take years before you reach crisis point.


Also, do not panic if your vet says your cat has lost a massive amount of kidney function. It is not usually possible to diagnose CKD until at least 66% (two thirds) of kidney function has gone (though the SDMA test may allow for an earlier diagnosis), and many cats are not diagnosed until 75% or even more has gone. Some cats manage quite well on extremely limited kidney function (less than 10%), so take a couple of weeks to see if your cat is one of them.


If your cat has high blood test results at diagnosis, there could still be hope. Cats often have off the scale test results when first diagnosed, but these results may not accurately reflect the true situation. Numbers can be artificially elevated if the cat is dehydrated, has an infection, has kidney stones or has high blood pressure. So again, take a couple of weeks to treat any problems that are present and then see how things stand.


Below I give an overview of which tests will help you spot possible problems, which symptoms are commonly seen, and which are the most helpful treatments. Please also see So Just How Sick Is My Cat? below.


I Don't Know What the Test Results Mean or Which Are Important


The tests which your vet runs will confirm the existence of CKD, and give some idea of how bad your cat's case is. Most people don't have the faintest idea what most of the test results mean, so to get you started, here is a summary which tells you what the main test results mean and what sort of symptoms they may cause. If you would prefer a very short summary, The Cat Practice has a brief overview. 


You should ask your vet for a copy of all the tests that are run, because these are helpful if you join Tanya's CKD Support Group. However, you can still join even if you do not yet have a copy of your cat's test results.

Tests: Bloodwork

Your vet will probably run:

  1. blood chemistry panel, which checks kidney function and looks for any other abnormalities caused by poorly functioning kidneys; and

  2. complete blood count (CBC), which looks at the cat’s blood cells. This enables the vet to check for anaemia, a common problem in CKD cats, and to look for signs of infection.

You will probably have 1-2 pages of results, but the seven items discussed below are the most important for you to understand at the beginning. If your cat's results show other items that are out of range, such as calcium, you should be able to find more information about these in the Diagnosis section.

If your vet has not addressed any results which are out of range, be sure to ask them why. Not everything needs treating (high cholesterol, for example, is not a worry in cats as it is in humans) but the items mentioned below do need treating if they are out of balance.

The USA uses a different measuring system to the rest of the world. Tanya's CKD Support Group tends to use the US measurement system, so if you join, you will get more responses if you convert your international values to American ones. See Diagnosis for ways to do this. There is no need to convert potassium or PCV/HCT, which are the same in both systems.

 BUN (blood urea nitrogen) or Urea

If you are in the USA, you should see blood urea nitrogen (BUN) on your cat's bloodwork. In Europe, you will probably see urea listed instead, which is not exactly the same thing but very close.


BUN is one of the two main measures of kidney function (the other one is creatinine). In a cat with CKD, BUN (or urea) will normally be elevated. BUN is a by-product of the breakdown of dietary protein during the digestive process. The kidneys filter it out of the blood and excrete it via urination. BUN rises in CKD because the damaged kidneys are no longer able to excrete it efficiently, so it builds up and makes the cat feel poorly.


BUN is not a major toxin in itself, but if it is elevated, then the chances are high that certain other toxins that are difficult to measure but which make the cat feel poorly will also be elevated.


BUN can also rise for other reasons though, such as dehydration, stress or a high protein diet, so it is not an entirely accurate measure of kidney function by itself.


However, it is important to try to control high levels of BUN because they can cause appetite loss, nausea and vomiting.


BUN may be controlled via dietary management and fluid therapy. Treatments for appetite loss, nausea and vomiting are also very useful and can make a CKD cat feel much better.


You can read about BUN in more detail in the Diagnosis section. 


Creatinine (Crea)

Creatinine is another waste product excreted through the kidneys. It is generally considered to be a more accurate measurement of underlying kidney function than BUN or urea because it is less affected by diet, stress and dehydration.


Because creatinine is the basic measure of kidney function, you will probably not be able to reduce it to within normal range in a CKD cat, but that does not mean that it cannot reduce from the level you see at initial diagnosis, so try not to panic if your cat has high levels to start with, especially if your cat is dehydrated or has an infection at the time of diagnosis.


You can read about creatinine in more detail in the Diagnosis section.. 



This is a relatively new test available exclusively from IDEXX Laboratories which aims to detect CKD at an earlier stage than is possible when measuring creatinine or BUN levels.


IDEXX claim that the SDMA test can potentially detect CKD when up to 40% of function has been lost, whereas traditionally you could only detect CKD when 60-70% of function had been lost. It also believes SDMA may rise up to 17 months before creatinine becomes elevated.


There is more information on the SDMA test on the Early Detection page.


Phosphorus (Phos, P or Pi)

Phosphorus and calcium are minerals which are important for nerve function, muscle contraction and bone formation. A healthy body has a natural balance between levels of phosphorus and calcium. CKD kidneys can no longer excrete phosphorus properly so levels of phosphorus rise (hyperphosphataemia), which can then adversely affect the cat's calcium levels, with potentially serious consequences (see secondary hyperparathyroidism). Not only that, but high phosphorus levels may make the CKD progress faster and can make a cat feel lousy. So controlling phosphorus levels is one of the most important steps in managing CKD and helping your cat feel better.


Symptoms of high phosphorus levels may include weakness, an unsteady walk, itching and scratching, loss of appetite, twitching and weight loss.


Your vet may say that your cat's phosphorus levels are within normal limits, but the high end of the normal range actually applies to kittens rather than to adult cats, particularly those with CKD. You should aim to actively control phosphorus levels once they are above 1.9 mmol/L (US: 6 mg/dl). This can be done by feeding a low phosphorus food (usually a therapeutic kidney diet) or by adding odourless, tasteless phosphorus binders to your cat's food, see below.


You can read about phosphorus in more detail on the All About Phosphorus page. 


Potassium (K+)

Potassium is an electrolyte (a type of salt), which the body needs in order to function properly at the cellular level. If potassium is out of balance, it can affect the muscles, including the heart.


Cats with CKD usually urinate a lot, and may also vomit, and this can cause a loss of potassium, leaving levels low in the cat's body. However, a few CKD cats (often, but not always those with high creatinine levels) have the opposite problem of levels of potassium that are too high.


Low potassium levels (hypokalaemia) can have various effects, such as weakness (especially in the back legs), twitching, hoarseness or constipation. Severe cases may be unable to lift their heads or have a stiff neck.


Although the range for potassium often starts at around 3.5 mEq/L (US) or 3.5 mmol/l (international), it is often recommended to treat CKD cats for low potassium when the level falls below 4.0 mEq/L (4.0 mmol/l). The goal is to have a level of around 4.4 mEq/L (4.4 mmol/l) or a little higher. The usual treatment is a potassium supplement in the form of a pill, though it does come in other forms too if your cat is difficult to pill.

Not all CKD cats have low potassium levels. Cats with a level of 4.4 mEq/L or 4.4 mmol/L or higher do not usually need potassium supplements. Cats with high levels of potassium (over 6.0) may experience twitching, seizures, and in the worst case scenario, even a heart attack.

There is information below about treating high or low potassium levels.


You can read about potassium in more detail on the All About Potassium page. 



Acidity levels in the body tend to become too high in CKD cats i.e. the body’s pH becomes too low — this is known as metabolic acidosis. This is not the same thing as gastric hyperacidity, which is excess production of acid in the stomach only.


Metabolic acidosis can have a variety of effects, including muscle wasting, a bony spine, back leg weakness, vomiting, mouth ulcers, twitching and seizures, so it is very important to diagnose and treat it if it is present.


Unfortunately many vets do not routinely monitor for metabolic acidosis, partly because it can be hard to measure. The best way to measure is via blood gas analysis, but if this is not possible, TCO2 or total carbon dioxide in the blood chemistry panel may give you some clues.


Treatments may include fluid therapy, potassium citrate or bicarbonate of soda.


You can read about metabolic acidosis in more detail on the Metabolic Acidosis page. 



The kidneys produce a hormone called erythropoietin, which stimulates the bone marrow to make red blood cells. Damaged CKD kidneys may no longer perform this task properly, and if red blood cells are not made, anaemia is the result.


PCV and HCT are both used to measure anaemia. Your vet will run one test or the other. PCV is not quite the same thing as HCT; but the difference between the two is too small to be concerned about. 


Technically, a cat is anaemic if his/her PCV level is below 30% (or with some laboratories, 25%), but you may not start to see any differences in your cat's behaviour until the level is in the low 20%s. Dehydration will make PCV look higher than it really is, so once a cat is rehydrated, PCV will often have fallen.


Symptoms of anaemia include weakness, loss of appetite, heavy breathing, feeling cold, eating litter or licking cement.


It is essential to treat anaemia. Cats with a PCV or HCT below 20% have severe anaemia, and you have to treat it quickly, because untreated severe anaemia can be life-threatening. Cats who are severely anaemic may appear very ill (though some of them adapt to the anaemia if it happens gradually, and cope quite well), but you should see a dramatic difference once the anaemia is under control. Treatments include iron or vitamin B supplements for milder cases, or the use of a synthetic hormone replacement known as ESAs (trade names are Aranesp, Epogen, Procrit, Eprex or NeoReocormon) for more serious cases.


You can read about anaemia in more detail on the Anaemia page. 


Other Tests

Blood Pressure

Hypertension (high blood pressure) is relatively common in CKD cats, because the kidneys produce renin, which controls blood pressure, but damaged kidneys may not do this effectively.


High blood pressure is very dangerous — it can cause strokes, seizures and blindness, and may even kill; but since it has few visible symptoms until a crisis occurs, it really needs to be measured with a blood pressure monitor.


Unfortunately, some vets do not have the equipment to measure blood pressure (even though it only costs about US$1000). Do ask your vet if s/he has this equipment, and if so, make sure s/he uses it to check your cat's blood pressure. If they do not have it, politely ask them to consider investing in it, and then call around other vets in your area (or ask your vet to do so) to see if you can find somebody who can measure your cat's blood pressure. If you cannot find anybody to measure it, check the All About Hypertension page for alternative checks, though they are far from ideal.


If blood pressure is consistently over 160, it should be treated. This is easily managed through the use of a medication called amlodipine (known as Norvasc in the USA and Istin in many parts of Europe).



This is a test of your cat's urine. It may include a check of urine specific gravity (USG), which tells your vet how dilute your cat's urine is (CKD cats usually have very dilute urine).


It often will also give the vet some information on whether your cat has a urinary tract infection (UTI).


Urinalysis can also show if a cat has proteinuria (protein leaking into the urine).


You can read about urinalysis in more detail in the Diagnosis chapter.



Sometimes vets want to perform an ultrasound of a cat's kidneys. This is not invasive and can be helpful if a cat has larger than expected kidneys (which may indicate cancer, a blockage of some kind or a genetic disease known as PKD), or if you suspect a kidney infection or kidney stones. Otherwise an ultrasound will usually simply confirm that a cat has CKD and adds nothing to the overall treatment plan. If this is the case for your cat, it is probably worth passing on an ultrasound and saving your money.


You can read about ultrasound in more detail in the Diagnosis chapter. 


There are a number of other tests which are occasionally offered, and you can find more information about them in the Diagnosis chapter. 


So Just How Sick is My Cat?


Most people panic if their cat's results are out of normal range, especially if they are many times higher than they should be. They are not exactly reassured when their vet then says "your cat only has x% of kidney function remaining." If the vet then uses the old style terminology, chronic renal failure, the word "failure" also terrifies most people when they first hear it.


Take a deep breath. Here are some crucial points to remember:

  1. It doesn't really matter how bad your cat's test results look at initial diagnosis, especially if your cat in in crisis (e.g. needs to be given intravenous fluids in hospital, or has an infection). You firstly need to stabilise your cat before you can see the true situation. Even then, some cats cope well with high numbers, hence your new mantra, treat the cat, not the numbers.

  1. It is normal not to be able to diagnose CKD until at least 66-75% of kidney function is gone. The What Happens in CKD page explains why this is the case. Even if you use the newer SDMA test, your cat will have lost at least 40% of kidney function before diagnosis.

  1. The word "chronic" is what matters. This means that in most cases, CKD is a progressive disease, and therefore death is not necessarily imminent. And chronic is usually treatable!

The How Bad is It? page gives you some idea of how serious your cat's bloodwork results are but remember, these are not the be-all and end-all. How sick your cat is depends upon whether s/he is in crisis or not at diagnosis, and also on how well your cat copes with CKD — some cats can cope astonishingly well with horrible bloodwork.


Let's talk a bit more about some common scenarios when you first get the diagnosis:

Cat in Crisis: Crashing

Many cats who are diagnosed with CKD are in crisis (known as "crashing"), often because of severe dehydration. CKD cats tend to urinate more as their kidneys deteriorate. They then drink more to compensate for the increased urination, but eventually they can no longer drink enough to keep up with the fluid lost from dehydration, and they crash.


Before you go to the vet (which you should do as soon as possible if you think your cat is crashing), here are some of the signs you may see:

  • the cat will often be unable to get comfortable and may lie in the meatloaf position;

  • you may notice a bad breath smell, and your cat may also have a generally strong body odour;

  • he/she will have dull, perhaps sunken eyes and not make eye contact;

  • your cat will probably refuse to eat and may also refuse to drink.

When you reach the vet, and bloodwork and other tests are run, you will usually be told that your cat's bloodwork values are very high. This occurs because severe dehydration artificially inflates most of the values.


I cannot emphasise this enough: it does not matter how bad your cat's bloodwork values are at initial diagnosis, particularly if s/he is severely dehydrated. You have to wait and see what they look like when the cat has been stabilised. My Thomas's BUN was 241 mg/dl at initial diagnosis (the top of the range was 36 mg/dl) yet he pulled through.


If your cat is in crisis, the first thing to deal with is the dehydration. This will usually be treated via intravenous (IV) fluids (a drip), which requires hospitalisation for a few days. Personally, I would want to put any cat of mine with creatinine of over 6 mg/dl (550 µmol/L) on IV for 3-4 days (one day is not enough).  As the cat becomes rehydrated, s/he should gradually start feeling and acting a little better, though some cats do not do well as in-patients and will only turn the corner once they return home.


The cat may continue to exhibit a loss of appetite, so it is essential that sh/e eats, via assist feeding if necessary. Since cats with high BUN levels tend to have problems with nausea and gastric hyperacidity, ask the vet to treat for that too.


A cat with high bloodwork will almost certainly have high phosphorus levels, and may also have anaemia, though anaemia may not be apparent in blood tests until the dehydration has been corrected. Hypertension (high blood pressure) may also be present. Treatment needs to be started for all of these as appropriate. I do not advise starting benazepril (Fortekor) treatments for cats with high creatinine levels because this medication may cause a worsening of kidney values when first begun (see Treatments).


Your cat may still have high numbers when you bring him/her home, but don't panic, they may continue to fall with a home treatment programme, as happened to our Thomas. Once your cat is home, you can follow the advice for the stable cat below.


The Stable Cat

If your cat is not in crisis, then creatinine levels will usually be 3.0-3.5 mg/dl (US) or 300-350 µmol/L (international) or less Yes, those numbers are still a lot higher than they should be but on Tanya's CKD Support Group they are considered medium level numbers. They may even be higher — some cats cope better with high numbers than others.

Whatever the level, if your cat is not in crisis and dehydrated, then it is highly unlikely that your cat needs intravenous fluids. I have heard of some vets putting non-crashing cats with creatinine of 3.0-3.5 mg/dl (US) or 300-350 µmol/L (international) or lower on IV fluids, which seems unnecessary to me — chances are these cats do not even need regular subcutaneous fluids, let alone IV fluids; plus it is much cheaper for you and less stressful for your cat if you can avoid IV fluids.

However, you will probably need to begin a home treatment programme. This need not be particularly complicated if your cat has been diagnosed early enough. In that case, you will probably merely need to focus on the things that will keep your cat stable (e.g. controlling phosphorus levels, and, for cats with creatinine over 3.0-3.5 mg/dl (US) or 300-350 µmol/L (international), perhaps giving sub-Q fluids regularly to prevent dehydration), and comfortable (e.g. controlling constipation or vomiting). Basically, you need to check the bloodwork and symptoms, see what issues may be a problem, and take the appropriate action.

Most people find they only need to spend 10-20 minutes a day dealing with their cat's CKD needs, and that includes time spent giving subcutaneous fluids (which not all cats need immediately). If you focus on any problems that are present and have a bit of luck on your side as well, you should soon see a big improvement in your cat's wellbeing. For more detailed information on the symptoms which you might be seeing, see the Index of Symptoms and Treatments page.

Even when a CKD cat is stable, it is normal for him/her to have the occasional bad day, particularly when first diagnosed. Try not to panic if this happens, just try to treat anything that may be contributing to the problem (e.g. if your cat is constipated, s/he won't feel great) and with luck you will find that once any problems are under control, your cat will have a reasonable quality of life overall.

However severe your cat's case may be, if I were to give you only one piece of advice, it would be to make sure your cat eats. Cats who go just a short time (a day or two) without eating are at risk of a condition called hepatic lipidosis, a potentially life threatening liver problem. Not eating can also worsen dehydration and make the cat very weak; whereas food in the stomach can often make a cat feel better and stronger. See below and the Persuading Your Cat To Eat page for information on getting food into your cat.

If Your Vet Has Recommended Euthanasia

I sometimes hear from people whose cats have only just been diagnosed, yet the vet is already recommending euthanasia. I hear things like "the vet said my cat has anaemia and it's untreatable, so I should put him to sleep", or "the vet says his bloodwork is so high that it can never reduce to a reasonable level" (this even for cats with creatinine of around 3.0-3.5 mg/dl (US) or 300-350 µmol/L (international)), and of course the classic "he's very sick, and it would be the kindest thing to do".


Often these vets do not even offer any IV (intravenous fluids) treatment for high number cats, or if they do, they only offer one day, tell the person their cat's numbers have not improved after that short stint, and recommend euthanasia. In some cases people are told even before their cat is placed on IV fluids that if s/he does not respond within 24 hours, they have to put their cat to sleep.


I'm not in the business of vet-bashing, but this approach does give me pause for thought. No vet has a crystal ball. And CKD cats can look horribly ill when they are first diagnosed, particularly if they are dehydrated. I was dehydrated myself one time following surgery, and I definitely looked as bad as I felt. Note I say that I felt bad; but I was not in actual pain. CKD is not generally considered to be a painful disease (end stage PKD, a genetic kidney disease, may be painful if some of the cysts rupture, but this is rare). Dehydration basically feels like a bad hangover, with a bad headache and a queasy stomach. CKD cats often have nausea and sometimes gastric hyperacidity, which feels like stomach ache. They may be constipated, and may have anaemia which makes them feel weak. But none of these things is outright painful. And all of these things are treatable, in fact often relatively simple treatments can soon make a CKD cat feel and act much better. 


So I would say that in most cases, you should definitely try treatments, for a period of two weeks if not longer, before opting for euthanasia. And if your cat has high bloodwork levels, then one day on IV fluids is simply not long enough to decide whether a cat is going to turn the corner or not! Read the rest of this page, particularly the Cat in Crisis section, see what problems your cat is experiencing, and do your best to treat them. I cannot promise that treating your cat is going to work. But there is a pretty good chance that it will. And even if it doesn't, at least you would have the peace of mind of knowing that you tried your best. And remember: it is not the vet's decision to put your cat to sleep, it is yours.


Commonly Seen Symptoms


This is a short list of symptoms which may be seen in CKD. Some of these problems, such as constipation, are not life threatening, but they can make a big difference to how well a cat feels. Others, such as not eating, can cause severe problems if left untreated.


The classic symptom for a CKD cat is to vomit clear foam, which is usually caused by gastric hyperacidity.


Other causes of vomiting include metabolic acidosis, or using certain types of antibiotics. Occasionally vomiting is caused by constipation, particularly if your cat vomits immediately after using the litter tray. 


If you are giving your cat sub-Q fluids and s/he regularly vomits after fluids, this may because of the type of fluids used.


Gastric Hyperacidity

Some CKD cats suffer from gastric hyperacidity or, in severe cases, stomach ulcers. If creatinine and particularly BUN/urea are elevated, it is possible that your cat has this problem too. Although recent research indicates that this is not as big a problem as previously thought, some CKD group members do find their cats seem to feel a lot better if appropriate treatments are used.


Your cat's stomach may gurgle a lot, or your cat may have little appetite, vomit clear foam, grind his/her teeth, or rests his/her head over the water bowl. Sometimes the cat will appear to want to eat, but will sniff the food, then walk away (this may also be a sign of mouth ulcers).  See below for possible treatments.


Mouth Ulcers

The toxins produced by the body can cause ulceration. Mouth ulcers may also be a sign of metabolic acidosis. You may see ulcers in the cat's mouth if you look inside, or in severe cases your cat may vomit blood (which may also be a sign of bleeding from further down the gastrointestinal tract).


Mouth ulcers are painful for the cat and often lead to a lack of appetite, or a desire to eat coupled with an inability to do so — the cat may approach the food bowl and sniff the food, then walk away.


Weakness, Especially in the Back Legs

Many CKD cats are weak at initial diagnosis. This may be because they are dehydrated, or anaemic. Other possible causes include high phosphorus levels, low potassium levels, metabolic acidosis, constipation and calcium imbalances.


If you and your vet can work out what the cause is and treat it appropriately, you should find that this symptom improves greatly.



The dehydration that accompanies CKD may cause constipation. Symptoms — apart from the obvious one of no poop in the litter tray — may include an ungainly walk, vomiting after using the litter tray, loss of appetite, pooping outside the litter tray, and, surprisingly, diarrhoea. Constipation can usually be treated easily and quickly.



CKD cats often howl, especially at night. Howling is commonly caused by high blood pressure. It may also have other causes such as toxins, deafness, hyperthyroidism, or occasionally just old age and possibly cognitive dysfunction (senility). Certain medications such as cyproheptadine (Periactin) or mirtazapine (Remeron),  both appetite stimulants, or anabolic steroids, can make a cat become vocal. 


Refusal to Eat

This is really common in CKD cats. Common causes include nausea, high phosphorus levels, dehydration, constipation, fluid retention, anaemia or loss of sense of smell. Many cats refuse to eat the therapeutic kidney diets in particular. Treating the cause will usually help, though some CKD cats will always need encouragement to eat.


Eating Litter

This is a classic sign of anaemia, though it may also occasionally be seen in cats with calcium imbalances. It should stop once the anaemia is under control.



Twitching is relatively common in CKD cats. Causes of twitching include high or low potassium levels, high blood pressure, high phosphorus levels, calcium imbalances (especially head twitching), hyperthyroidism or vitamin B deficiency. Twitching may also be caused by high toxin levels. If your cat only twitches while you are giving fluids, it is probably caused by either the type of fluid used or by giving cold (room temperature) fluids.



Sometimes CKD cats go blind, and this may happen suddenly. Look at your cat's pupils and check whether they are enlarged or very black, even in bright light.


Do not panic. The most common cause of blindness in a CKD cat is hypertension (high blood pressure), but if you start the correct treatment (a drug called amlodipine (Norvasc or Istin) as quickly as possible, your cat has a reasonable chance of regaining his/her vision.


Kidney Stones

Kidney stones can be very painful but in some cases, there may be no obvious signs, since cats instinctively try to hide pain. In other cases the cat may be subdued and lethargic and not want to eat. Some cats will have blood in the urine (haematuria) or frequent kidney infections.


Some cats urinate more, but others exhibit reduced urination. If your cat is unable to urinate, this is a medical emergency and you need to get to a vet as quickly as possible.


See Kidney Stones for more information.


Pyelonephritis or Urinary Tract Infections

Cats with a UTI or chronic pyelonephritis (a kidney infection) often do not show any symptoms.


Cats with acute pyelonephritis will often be obviously ill, e.g. not eating, sensitive to the touch in the lower back or abdomen, and/or have a fever.


CKD cats with these infections need a course of antibiotics, see below and Pyelonephritis and Urinary Tract Infections.



Proteinuria means there is excess protein in the urine. The most common symptom is foamy urine. It is important to treat proteinuria because it may make CKD progress faster. Unfortunately it can be difficult to treat, but certain heart medications may help, see below and Proteinuria.


My Cat Has Symptoms Not Listed Here

If the symptom you are interested in is not here, check the lengthy list of possible symptoms on the Index of Symptoms and Treatments page, together with detailed links to possible causes and appropriate treatments. And don't panic, you are not going to be faced with all these problems!


Commonly Used Treatments


The following is a list of some of the treatments which you may be offered. If you are in the UK, I can virtually guarantee that you will only be offered a therapeutic kidney diet, benazepril (Fortekor), and occasionally Ipakitine or Pronefra; but many of the other treatments are equally, if not more important, depending upon your cat's condition. 


Diet is a popular and effective way of trying to treat CKD. Your vet may prescribe a therapeutic kidney diet, which is a food that is relatively low in protein and phosphorus, and which has other benefits. If your cat will eat these foods, then by all means feed them, though try to introduce them gradually, which increases the chances of your cat accepting any new food.


Unfortunately, loss of appetite is very common in CKD cats, and these foods can be a little dry and many cats find them lacking in flavour. Your vet may tell you it is essential that your cat only eats this food, but cats who go just a short time (a couple of days or so) without eating are at risk of hepatic lipidosis (fatty liver disease) where the liver starts to function abnormally; this can happen after just a day or two of not eating, and can be life-threatening. Mar Vista Vet has more information about this. So if your cat refuses to eat the therapeutic kidney food, don't panic — not eating is far worse for him/her.


If you are in the middle of a crisis, feed whatever your cat will eat — baby food (without onion), Hill's a/d. Anything to get some nourishment into him/her. See the Persuading Your Cat To Eat page for tips.


Also try to treat any possible problems, such as nausea, anaemia, etc.. Once these are under control, you may well find that your cat’s appetite returns.


You can look into getting your cat onto a better diet once s/he is more stable, but be sure to introduce any new food gradually. If you do not succeed, you don't need to despair: it is still more important that your cat eats than that he/she eats therapeutic kidney foods. In fact, the current thinking is that feeding a reduced protein diet might not be appropriate for cats in the earlier stages of CKD, though therapeutic kidney diets do have many other useful characteristics (see Which Foods to Feed). However, once BUN (urea) is consistently over 60-80 mg/dl, most cats tend to feel better with less protein in the diet to process.

If your cat refuses to eat a therapeutic kidney diet, aim at least to feed a food low in phosphorus. There is a lot more information on the Nutritional Requirements, Which Foods to Feed and Persuading Your Cat To Eat pages.



Vitamin B is a water-soluble vitamin, and is often lacking in CKD cats, who lose much of their vitamin B through urination. A lack of vitamin B may lead to a lack of appetite, or occasionally may cause twitching or itching. Vitamin B deficiencies are also known to cause non-regenerative anaemia. Your vet may therefore suggest a supplement in order to avoid these problems. British vets often give vitamin B injections, but you can also give vitamin B orally.


In contrast, additional doses of vitamins A, C and D are not appropriate for CKD cats.


Please see Vitamin B for more information on the B vitamins and Nutritional Requirements for more information on the other vitamins.


Appetite Loss, Nausea and Vomiting

These are common concerns in CKD cats. Although nausea is not visible, it is thought to be present in many CKD cats.


If you are seeing both loss of appetite and vomiting, particularly vomiting white foam, plus other symptoms such as resting the head on the water bowl or teeth grinding, then the most likely explanation is the increased toxins associated with CKD (sometimes referred to as uraemia). If you focus on treating this, which is usually pretty manageable, it will help your cat feel much better. 


If you like a more holistic approach, a cheap, effective treatment is slippery elm bark, which seems to help many CKD cats.


Other popular treatments include ondansetron (Zofran) or maropitant (Cerenia).


Some people use medications called histamine H2 antagonists, such as famotidine (Pepcid AC) or ranitidine (Zantac 75), or proton pump inhibitors (PPIs) such as omeprazole. Essentially these medicines block the overproduction of stomach acid, so the cat doesn't feel so queasy. The good news is, these medicines are available over the counter in most countries (although you should of course obtain your vet's approval to use these treatments) and are not expensive, and they usually work fast.


Here is more information about these issues:

Fluid Therapy

If your cat is severely dehydrated with high blood values at diagnosis, your vet will probably offer intravenous (IV) fluid therapy (a drip) to rehydrate your cat.


If your cat has lower numbers upon diagnosis or following IV treatment, but the creatinine is over 3.5 mg/dl (USA) or 300 µmol/L (international), you will probably find that s/he does better with regular subcutaneous fluids (known as sub-cuts in the UK) to help prevent dehydration. Unfortunately, whilst subcutaneous fluids (sub-Qs) are routinely offered in the USA, they are very uncommon and hard to obtain in Europe.


Most cats receiving sub-Qs need about 100ml a day, no more; some cats need less. Your vet can show you how to give sub-Qs to your cat yourself at home, and they can really help to make your cat feel better, although you do need to be sure that your cat does not have a heart condition before using them.


If your cat has creatinine below 3.5 mg/dl (USA) or 300 µmol/L (international), the chances are that s/he can maintain hydration without sub-Qs. Sub-Qs are a strain on the kidneys, so there is no point giving them before the benefits outweigh the risks. If your vet recommends them for a cat with creatinine below 3.5 mg/dl (USA) or 300 µmol/L (international), ask why.


See Fluid Therapy for more information.


High Phosphorus Levels

If your cat's phosphorus level is above 6 mg/dl US or 1.9 mmol/L international, and you are not feeding a therapeutic kidney diet, or if the level is this high despite feeding a therapeutic kidney diet for 3-4 weeks, you should ask your vet about using a phosphorus binder. Phosphorus binders bind with the excess phosphorus in cat food and therefore reduce the load on the kidneys. They must be given with food in order to bind properly, and ideally an hour or so apart from other medications.


A popular choice is aluminium hydroxide. US vets may offer this in the form of AlternaGel, but this is peppermint-flavoured, which most cats hate. Aluminium hydroxide can be obtained in odourless and flavourless formulations and simply added to the cat's food without the cat knowing.


You may be offered other binders such as Ipakitine (Epakitin) or Pronefra.


The All About Phosphorus page explains more about phosphorus control.


Phosphorus Binders has information on your binder choices.


Hypertension (High Blood Pressure)

Up to two thirds of CKD cats have hypertension, so do ask your vet to monitor your cat's blood pressure; many do not do so routinely.


If your cat has suddenly gone blind, the most common cause is hypertension; and if you act quickly enough, your cat may be able to regain some or all of his/her sight.


Even if your cat has not gone blind, if hypertension is present, it must be treated. The treatment of choice for CKD cats with hypertension is a drug called amlodipine (trade names are Norvasc or Istin) This is very well tolerated by the majority of cats, is less likely than some other treatments to cause the opposite problem of low blood pressure, and is the only treatment which gives your cat a chance of regaining his/her sight if it has been lost.


You can read about high blood pressure in more detail on the All About Hypertension page. 


Appetite Stimulants

There are two commonly used appetite stimulants in cats, mirtazapine (Remeron) and cyproheptadine (Periactin). They are usually very effective, but may have side effects, such as making the cat agitated, causing howling etc.


Whilst these medications may stimulate your cat to eat, it is better if you can find the cause of your cat's inappetence and treat it. But appetite stimulants can certainly be a useful tool for inappetence at initial diagnosis.


The Persuading Your Cat To Eat page has more information about appetite stimulants.



If your cat’s PCV or HCT level is below 30% (25% for some laboratories), your cat has anaemia. Treatment depends upon how severe the anaemia is and whether it is caused by the CKD:

  • If PCV is between 20% and 30%, an iron supplement and/or B Vitamins may be enough to control it, whatever the cause.

  • if PCV is below 20%, your cat has severe anaemia and you need to treat it more aggressively. If this is CKD-related non-regenerative anaemia, you should consider using erythropoiesis stimulating agents (ESAs) which have the trade names of Aranesp, Epogen, Procrit, Eprex or NeoRecormon, particularly if your cat's PCV is closer to 15% than to 20%. Darbepoetin (Aranesp) is usually the best choice. Many vets are extremely negative about using ESAs, but you need to understand that severe anaemia will kill your cat before the CKD does. We began using an ESA (Eprex) for Thomas when his PCV reached 18%. For us, it was a no-brainer since the alternative was to sit back and watch Thomas die of anaemia, and we never regretted using it.

  • The above treatments take time to take effect. If your cat's anaemia is particularly severe (PCV below 15%), you may need to consider a blood transfusion to tide you over until the other treatments kick in.

Please see the Anaemia page and Erythropoiesis Stimulating Agents page for more information.


ACE inhibitors and ARBS: benazepril (Fortekor) or telmisartan (Semintra)

If you are in the UK or Canada, your vet may well prescribe a drug called benazepril (Fortekor, or Lotensin in USA). This drug is actually a heart medication (an ACE inhibitor) approved in Europe and Canada for the treatment of chronic kidney disease in cats.


Another drug, telmisartan, an ARB (angiotensin II receptor blocker) is approved in the USA for the treatment of hypertension and is approved in Europe for the treatment of proteinuria in cats and may be offered instead.


There are pros and cons to using these medications to treat CKD cats. They may be of benefit to cats with proteinuria, but are sometimes offered to CKD cats without proteinuria. My main concern is that when first used, these medications may cause an increase in creatinine, which might be enough to push a cat with high bloodwork over the edge. They should never be given to dehydrated cats.


If your cat has hypertension, particularly if s/he has gone blind, amlodipine (Norvasc or Istin) is the drug of choice for CKD cats with hypertension, and may enable your cat to regain his/her sight.


For more information about using ACE inhibitors and ARBS, please see Proteinuria.


Mouth Ulcers

Slippery elm bark, which as mentioned above can help with appetite loss and nausea, can also be made into a syrup and used to help heal mouth ulcers —— this has been found to be a very effective treatment by many people. See Holistic Treatments for more information about slippery elm bark and how to make the syrup.


For severe mouth ulcers, antibiotics may be necessary; while for really obstinate ulcers, you may need to consider using a treatment called sucralfate, which forms a protective coating over the ulcers and allows them to heal. Trade names for this drug include Antepsin in the UK, Carafate in the USA and Ulcogant in Germany.


The Treatments page has more information about treating mouth ulcers.



Slippery elm bark may also help with this (see Holistic Treatments).


Other treatments include MiraLAX or Lactulose.


See All About Constipation for more information.


Potassium Imbalances


Low Potassium

If your cat’s potassium level in blood tests is 4.0 mEq/L (4.0 mmol/L) or lower, ask your vet for a potassium supplement. One popular choice is Tumil-K. However, never give potassium supplements without your vet's knowledge and approval — high potassium levels can be dangerous. See All About Potassium for more information. 


High Potassium

If your cat's potassium levels are high, the first thing to do is to run another blood test because the most common cause of high potassium levels is an error in the measurement. If your cat really does have high potassium levels, the All About Potassium page has more information on how to deal with this. 


Metabolic Acidosis

This means the cat's pH levels in the body are out of balance, causing excess acidity.


If your cat’s bloodwork contains something called TCO2 or CO2 and this is below 15, ask your vet about using bicarbonate of soda or potassium citrate to help with this problem.


See Metabolic Acidosis for more information.



If you are in the UK and other parts of Europe, you may be offered steroids. If you are in the USA, most vets do not seem to use steroids routinely.


Steroids are intended either as an appetite stimulant or as a general pick me up, but they do have possible risks. I did find Thomas did better overall on steroids but he was extremely ill when first diagnosed; cats who are diagnosed early probably would not benefit particularly. You should familiarise yourself with the possible risks before deciding whether to use them.


For more information about using steroids, please see the Treatments page.



Antibiotics are not routinely used in CKD, though some vets appear to prescribe them routinely. However, they may well be necessary for cats with dental problems or severe mouth ulcers, and a course is essential for cats with urinary tract or kidney infections.


The Pyelonephritis and UTIs and Treatments pages have more information about antibiotics.



Azodyl is essentially a type of probiotic. Probiotics are commonly used to re-balance the bacteria in the gut, particularly after using antibiotics. There is more about them in the Treatments section.


Azodyl contains strains of three patented types of bacteria, and the manufacturers of Azodyl claim that their strains of these bacteria have a particularly high affinity for some of the major uraemic toxins found in CKD. Azodyl is intended to bind with and reduce the levels of these uraemic toxins in CKD cats.


I have heard reports from several people who have used Azodyl. Most people seem to think it has helped their cats, though several others have said that it made their cats vomit, and some people think it did not make any difference.


Azodyl is currently only available in the USA and Canada, although it can usually be shipped to other countries if required.


There is more information about Azodyl in the Treatments section. Personally, I do not consider it to be an essential treatment.


Meloxicam (Metacam)

Meloxicam is a non-steroidal anti-inflammatory drug (NSAID). It is a very effective painkiller, but unfortunately when given in too high a dose, in some cases it may lead to acute kidney injury (though it is actually also being researched to see if it might help slow the progression of CKD in cats).


If your cat is taking meloxicam when or shortly before CKD is diagnosed, discuss with your vet whether to continue using it.


There is more information about meloxicam here.


Financing Treatment


It is all very well knowing about the treatment options available, but that can be very depressing if money is a factor, as it is for most people. It can be particularly horrifying if your cat crashes and requires hospitalisation — some large city hospitals charge a fortune for such services.


The good news is that you should not need all the treatments described above; and for home treatments, it is usually possible to purchase most of the supplies you require cheaply online. For the average cat who needs sub-Q fluids, phosphorus binders and treatments for nausea or constipation, it is often possible to spend as little as US$5 a week treating your cat once s/he is stable. Other treatments, including erythropoiesis stimulating agents such as darbepoetin (Aranesp) or epoetin alfa (Epogen, Procrit or Eprex), can also be obtained at more reasonable prices than many vets realise, if you know where to look.


The Coping with CKD page gives tips on coping with the financial burden and finding ways of paying for your cat's care, whilst the Obtaining Supplies Cheaply section gives details of reasonably priced suppliers in the UK, Canada and USA.


Pat's Great Advice for Those New to CKD


That is your crash course in CKD. Unfortunately I know you are probably still feeling overwhelmed, so here is some advice for you from Pat, who has been in your shoes. Pat cared for her cat SEM when he had CKD, and she wrote a wonderful message to a person with a newly diagnosed CKD cat. She says it all so well here, far better than I could, that I asked her if I could repost her message here.


"I am sorry you have a need to be here but you have come to a good place. First, I can't think of a single individual who hasn't landed here in an emotional heap. It seems not to matter the numbers of the cat or the circumstances of the individual, everyone is devastated.


"So... your sweet cat is exactly the same cat the day before the diagnosis as the day after. The only thing that has changed is information in your head. These cats set such very fine examples for us — if they're feeling well, all is well. If they're not feeling well, they need some help. My advice is to face the fear squarely, see it for what it is, and know that it has now moved in with you. But it doesn't require your attention, let it simmer away on the back burner with the lid on and do as it will. In the meantime, you can educate yourself by reading the overwhelming CKD site bit by bit so you can get a jump on anything that develops. That old stitch in time saves nine :-)


"There is no cure for CKD (at present). And life itself is a terminal condition. There's simply nothing to be done about that. But there is something to do about cats and CKD and that something is to learn about kidneys and their function and what helps and what doesn't and what shouldn't be done. In the meantime, your girl will not be worrying her pretty head, she will be doing normal cat things :-)


"Do get a copy of your blood work and post the numbers to the group (with normal ranges included), and keep copies of all tests and lab reports etc. It is hard dealing with a chronic condition, which is why I urge you to deal with the crux of the matter now and set it aside. There's no way to avoid going up and down emotionally with these cats, that will happen as a matter of course, but if you can, see your cat as very much alive because she is and should remain so for a good long time to come with your attention and love. And her heart is doing the beating, her lungs the breathing, her tongue the washing up. Life still courses through her. If you go crazy, she will have lost a loyal and articulate ally. We surely don't want that to happen:-)"


One Last Word


I know CKD is a scary diagnosis — I've been there three times. The first time, with Tanya, I was not online and although I tried to help her, in retrospect there was so much more I could have done to help her.


It is different for you. You have this website. By all means feel frightened, but then tell yourself you are going to do your best to help your cat. Read the site. Educate yourself about the basic issues above. Join Tanya's Support Group.


In the vast majority of cases, there is hope. You can do it!




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This page last updated: 25 August 2020

Links on this page last checked: 25 August 2020








I have 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.



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