Tanya's Comprehensive Guide to Feline Chronic Kidney Disease

Although this website is relatively simple in its design, it is also extremely comprehensive, and sometimes people feel overwhelmed at initial diagnosis and just want a CKD primer. Here I am giving you the key issues on which to focus in order to help your cat feel better and give him/her the best chance of survival.

There are a lot of options out there for treating CKD, and many products competing for your money. If your cat has just been diagnosed, or his/her condition is worsening after a period of stability, you may be tempted to buy into these products, hoping for a miracle cure. Unfortunately, although many of the treatments out there are quite expensive, very few of them are essential, and many of them are unproven. If your cat has a problem with any of these key issues, this page will help you understand which are the proven, essential treatments for those issues. If you are short of money, you will be relieved to hear that the majority of the treatments for these key issues are usually available at pretty reasonable prices.

There are eight key issues, which might sound like a lot. However, many cats will not need all eight to be managed immediately, in fact they may never have problems with some of them; but I would read up on them all anyway, just so you are prepared in case of need.

So take a deep breath, and start learning about CKD. I suggest you read this page all the way through the first time, so you get an overview of the main issues that you may need to deal with. Then you can go through it all again and click on the links which take you to more in depth information on the topics which affect you at the moment.

What to Feed Go to page

I know your vet may have told you that your cat simply must eat the prescription diet, that anything else will kill him or her. Eating that food is certainly the ideal. If your cat will eat it, fabulous! Feed it to your cat happily.

But in 11 guidelines for conservatively treating chronic kidney disease (2007) Polzin D, Veterinary Medicine December 2007, Dr Polzin makes the shocking observation that "in many or most dogs and cats with chronic kidney disease, death or euthanasia results directly or indirectly from starvation."

Think about that for a moment. Many CKD cats do not die because they have CKD. They die because they are allowed to starve to death! Are you going to allow your cat to starve to death?

Food is life. Nobody can live long without it. So the first rule is:

GET FOOD INTO YOUR CAT!

If your cat falls into the extremely large category of cats who would rather starve (literally) than eat prescription food, then don't force the issue. Feeding your cat won't kill him or her, but starvation will, plus if you allow a cat to go without eating, s/he can quickly develop a potentially fatal liver disease called hepatic lipidosis.

With time and a bit of luck, you will be able to get your cat onto a diet appropriate for a CKD cat (though quite a lot of people never manage that, and their cats still do fine). But if your cat has not eaten today, then right now, right this minute, I would like you to go and give your cat some food he or she is prepared to eat. Just make sure it doesn't contain any garlic or onion.

If you are in the USA, Fancy Feast is a good bet - you can read here which are the best varieties to try. Or try baby food - many cats will eat this when they will eat nothing else. Or simply feed your cat's favourite food. It doesn't matter what it is, as long as it gets eaten. Your stress levels will immediately go down if your cat eats something. Your cat will feel better with something in his/her tummy.

Longer term there are a lot of things to learn about food and nutrition for CKD cats, and ways to encourage your cat to eat the prescription diet. Here are links with more detailed information on dietary and nutritional issues:

But always, the most important thing is that the cat eats.

Vomiting, Loss of Appetite, Weight Loss Go to page

Vomiting and weight loss are often the symptoms that lead to the initial diagnosis of CKD. The vast majority of CKD cats will vomit a lot, at least at first.

This will usually be combined with a loss of appetite. Many CKD caregivers are tearing their hair out trying to get their cats to eat. It is stressful for you, it is stressful for your cat.

Why do CKD cats stop eating and/or vomit a lot? There are a number of possible causes. The site will help you work out if there is a particular reason why your cat won't eat, and help you find a way to solve that problem. The most common causes are dehydration, high phosphorus levels, anaemia and excess stomach acid.

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 increased stomach acid caused by the CKD. If you focus on treating this, which is usually pretty manageable, it will help your cat feel much better.

The best treatment for vomiting caused by stomach acid is a type of medicine called histamine H2 antagonists. Examples of such medications are Pepcid AC (famotidine) and Zantac 75 (ranitidine). Essentially what these medicines do is block the production 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. If you like a more holistic approach, a cheap, effective treatment is slippery elm bark.

If these treatments don't work, there are other possible causes of these symptoms. But the majority of CKD cats do have stomach acid and will benefit from having it controlled.

Here is information on these issues:

Hydration Go to page

Another common symptom that may lead to the initial diagnosis of CKD is increased urination. Because they are peeing more, CKD cats usually drink more too, but eventually they cannot drink enough to keep up and they become dehydrated.

Some cats who become dehydrated will "crash". This usually happens because they are severely dehydrated, and as a result their bloodwork results will be extremely high. Don't worry about this, because you cannot assess how severe the CKD is until the cat has been stabilised and rehydrated.

Usually cats who crash will need to be treated in hospital and placed on a drip (intravenous fluids or IV) for a few days to help them become stabilised. One day is unlikely to be long enough, and even after a few days, their numbers may not improve immediately. Do not be talked into euthanasia at this point, give your cat a chance to come home and gradually improve.

Many CKD cats will not crash and will not need to be hospitalised, but they may still be experiencing dehydration. For these cats, giving sub-cutaneous (under the skin) fluids at home, known as sub-Qs in the USA and sub-cuts in the UK, is a very helpful treatment. However, it is best not to start this treatment too early, or to be too aggressive with the treatment. Sub-Qs may be risky for cats with heart disease.

Generally speaking, cats with creatinine over 3.5 (US) or 300 (international), will benefit from sub-Qs. The usual amount to give is around 100ml of fluid a day. Unfortunately, sub-cuts are relatively uncommon in the UK, so you may need to persuade your vet to allow you to give them.

Here are links on fluid therapy:

Constipation Go to page

Constipation is pretty common in CKD cats. Constipation can be really uncomfortable and can cause vomiting, weakness and loss of appetite, so if your cat has it and you get it under control, your cat should feel a lot better and a lot happier.

Constipation is not difficult to treat in most cases. The usual treatment is a medication called Lactulose, though in recent times a similar type of product called Miralax is becoming increasingly popular. Lactulose requires a prescription in the USA but is over the counter in most other countries. Alternatively you can use a natural product called slippery elm bark. All these treatments will start working quickly, though if the cat is severely backed up, the vet may need to perform an enema first; but these treatments should then keep the constipation under control.

You can read more about constipation on the Constipation page:

Potassium Imbalances Go to page

These are very common in CKD cats. In most cases, the cat will have potassium levels that are too low. This is because the body loses potassium via the increased vomiting and urination usually seen in CKD.

The main symptom of low potassium levels is weakness, especially in the back legs (there are other causes of this but low potassium levels are a very common cause). It may also cause constipation and cause problems holding the head up.

Reference ranges for potassium vary from lab to lab but as a general rule the magic number at which action is required is 4. Take a look at your cat's blood test results or ask your vet what the level is. If you cannot see a measurement for potassium, look for K or K+, the chemical symbol for potassium.

Potassium Level	Treatment Plan
Below 4	Ask your vet about using a potassium supplement.
Between 4 and 4.3	Treatment is not essential. However, discuss with your vet and be prepared to take action if the level falls below 4, or if your cat already has symptoms of potassium deficiency.
4.4 or above, and still within lab range	Target range. Relax - you don't need to do anything. Scratch potassium from your list of worries for now.
Over 6	Worryingly high. Ask vet to re-check level because with luck it is a false reading.

Treating low potassium levels is pretty easy. You simply use a potassium supplement. These come in oral or injectible forms, and they work fast. When I adopted him, my Ollie was unable to walk properly because of low potassium levels. Within two doses (an evening dose and another dose the next morning), I could see a dramatic improvement. After 48 hours he could walk normally again!

One thing to bear in mind: many vets do not realise that you need potassium to be above 4, preferably around 4.4. Ollie's level was 3.5, and for the lab my vet uses, that was the bottom end of normal, so she didn't think he needed a supplement because technically it was normal. But I asked her to humour me, and we were both thrilled to see how well it worked. Being within normal range was simply not enough for Ollie and many other CKD cats.

But please do not rush to use a potassium supplement unless it is truly needed, and never use it without your vet's knowledge and approval. High potassium levels can be very dangerous. Occasionally a CKD cat will have high potassium levels, and others may develop them if too much potassium supplementation is given, or if it's given when it's not needed.

If your cat's level is above 6, then you need to do something about it because it is potentially very dangerous (high potassium levels can cause seizures or even a heart attack). Fortunately, in the majority of cases, if the potassium level is 6 or over, it is a false reading. So the first thing to do is to ask your vet to run bloodwork to check your cat's potassium levels again.

You can read more about potassium here:

Control of Phosphorus Levels Go to page

Healthy kidneys excrete phosphorus from the body. The damaged kidneys of a CKD cat are unable to do this as effectively as they should, so phosphorus levels in the body increase. High phosphorus levels will make a cat feel lousy, and can even make the CKD progress faster, so it's really important to get them under control. Symptoms of high phosphorus levels include loss of appetite, itching and weakness.

The prescription foods for CKD cats contain reduced levels of phosphorus (plus lower levels of protein, though it is debatable how essential that is, see the Nutritional Requirements page). If your cat's phosphorus levels are only mildly elevated, and your cat is prepared to eat prescription food, the phosphorus levels will probably go down to a safe level. But if your cat has high phosphorus levels or refuses to eat a prescription diet, you will need to take action.

Remember the magic numbers above for potassium, 4 and 6? Well, to make things easier for you to remember, if you are in the USA, these are the magic numbers for phosphorus too. Ideally you want your cat's phosphorus level (in blood tests) to be around 4. And you need to start taking action if the level is above 6. The higher the level, the more important it is to control. So:

Current Phosphorus Level: International Values	Current Phosphorus Level: US Values	Treatment
1.3 mmol/L or below	4.0 or below	No need to take any action at this time, scratch it from your list of worries for now.
Between 1.3 and 1.9 mmol/L	Between 4.0 and 5.99 mg/dl	No need to take action at this time, but monitor levels and be prepared to take action should the levels rise.
Between 1.9 and 3.24 mmol/L	Between 6.00 and 10.00 mg/dl	Either feed a prescription diet, or if you are not feeding such a food, begin using phosphorus binders.
Over 3.25 mmol/L	Over 10.00 mg/dl	Even if you are feeding a prescription diet, you may need to use phosphorus binders to get the levels down. If you are not feeding a prescription diet, you definitely need to use phosphorus binders.

What are phosphorus binders? Well, as the name suggests, they are products which are intended to bind with the excess phosphorus in food in the intestine and thus stop the phosphorus being absorbed into the cat's body.

The best type of binder is aluminium hydroxide, which comes in powder or gel form for you to mix with your cat's food. Many vets recommend products which are peppermint-flavoured, which most cats hate. However, odourless and tasteless binders do exist and are available without prescription. Phosphorus binders can be hard to find locally but are easily obtainable online at reasonable cost. They take about a week to kick in, and once your cat's phosphorus levels are at the desired level, your cat should be feeling and acting a lot better, and problems caused by the high phosphorus levels should disappear.

The All About Phosphorus page has information about high phosphorus levels and phosphorus binders, including which to use and how much:

Hypertension (High Blood Pressure) Go to page

This is pretty common in CKD cats unfortunately, and may even arise in cats with mild CKD. It's even more likely if your cat has hyperthyroidism (an overactive thyroid).

Unfortunately hypertension can be hard to detect. It may cause a cat to be lethargic or to twitch, but not every cat will show symptoms, or will not show any symptoms until more severe ones become apparent, such as seizures, blindness or a stroke. If your CKD cat has recently gone blind, the most likely cause is hypertension. The good news is, if you start treatment as quickly as you can, your cat may regain some or all of his vision. If your CKD cat is having seizures because of hypertension, getting it under control should stop the seizures.

Ideally you want to get your cat's blood pressure checked regularly. Unfortunately not all vets have the equipment to measure blood pressure in cats. If your vet cannot test your cat's blood pressure, but your cat has gone blind, I would ask to start treatment anyway.

Here is a guide as to when to start treatment:

Systolic Blood Pressure Measurement	Risk of Damage to Organs	Treatment Plan
Under 150	Minimal	No treatment necessary at this time, scratch it from your list of worries for now.
150-159	Mild	Treatment is not normally necessary. However, it may be appropriate to begin or increase blood pressure medications if ocular or neurological signs are present.
160 - 179	Moderate	Begin or increase blood pressure medications.
Over 180	Severe	Begin or increase blood pressure medications.

Some vets (especially those in Europe) prescribe drugs called ACE inhibitors (a common one is benazepril, trade name Fortekor) to treat hypertension. However, the absolute best treatment for hypertension in cats is a medication called amlodipine (trade names are Norvasc in the USA and Canada and Istin in Europe and Australasia), which is not too expensive. Why is it the best treatment?

It has very few side effects.
It is unlikely to cause blood pressure to fall too far, which is an important consideration if your vet is not 100% sure if your cat has hypertension because s/he lacks the equipment to measure blood pressure, or your cat is too agitated to get an accurate reading.
If your cat has gone blind because of hypertension, amlodipine may help the retinas re-attach and your cat could regain some or all of his/her vision. Fortekor will not help with blindness.

Amlodipine takes about a week to get blood pressure under control, and some cats may become lethargic for a few days until their bodies get used to the medication, but after that the cat should start feeling and acting better.

Here is more information on hypertension:

Anaemia Go to page

Anaemia occurs in CKD cats because the kidneys produce a hormone called erythropoietin which regulates the production of red blood cells. Damaged kidneys can no longer produce this hormone properly, so fewer red blood cells are produced and anaemia can occur. This type of anaemia is known as non-regenerative anaemia.

In most cases, this type of anaemia does not occur until the CKD is relatively advanced i.e. when creatinine is over 5 (US) or 450 (international), although there are exceptions to this rule. But if your cat has anaemia and creatinine is under 5 (US) or 450 (international), I would ask your vet to rule out other possible causes, such as gastro-intestinal bleeding, or infection or inflammation, because they need different types of treatment.

Anaemia makes a cat feel really tired and weak. It can also cause loss of appetite and breathlessness. In the worst case, it can cause heart problems. So you see, it's very important to treat it if it is present.

The degree of anaemia is determined by the levels of PCV or HCT in your cat's blood work. The following table shows the degrees of anaemia and the best treatments to use for each stage, assuming this is anaemia caused by a lack of erythropoietin:

Level of PCV or HCT	Severity of Anaemia	Treatment Plan
Under 15%	Very severe	You need to start human erythropoietin. If symptoms are present, you may also need to consider a blood transfusion to tide your cat over until the human erythropoietin kicks in. Also use B vitamins and iron.
Between 15% and 19%	Severe	You will probably have to start using human erythropoietin, plus B vitamins and iron.
Between 20 and 25% (or bottom end of normal range)	Mild	Begin using B vitamins and iron e.g. NutriVed or Pet-tinic.
Within normal range	Not anaemic	No treatment necessary at this time, scratch it from your list of worries for now.

Human erythropoietin is sold under the names of Epogen, Procrit, Eprex, NeoRecormon or Aranesp. It is a very effective treatment, but some vets do not like to use it because, since it is a human product, there is a possibility of cats developing antibodies to it. However, this does not happen that often (certainly not as often as many vets seem to think it does), and when it does, it simply means that the anaemia gradually returns and you are back where you started. But if this is going to happen, it does not normally happen for 4-5 months, during which time your cat will have regained a good quality of life.

Make no mistake, anaemia can kill. If a cat has severe anaemia (PCV or HCT between 15% and 19%), in most cases you will need to start using erythropoeitin, though you could simply try B vitamins and iron for a week or two instead and see if they help. However, this can be a bit of a risky approach because erythropoietin products take a couple of weeks to kick in, during which time your cat could be getting sicker.

Some vets think Epogen costs hundreds of dollars but that is nonsense - you can buy it from many pharmacies in the USA for as little as US$30 a vial, and a vial contains approximately 4-5 treatments, depending upon how much your cat weighs. In the UK you will pay around £90 for 12-24 treatments of Eprex. Initially you will have to give three treatments a week, but once the anaemia is under control, the treatment may be given as infrequently as every ten days. Aranesp is more expensive, but is given much less frequently, so the cost tends to work out about the same.

Note: iron should not be given to cats suffering from an infection.

Here are pages which tell you all you need to know about anaemia in CKD cats, including where to obtain Epogen cheaply:

Metabolic Acidosis Go to page

[To be expanded upon]

Kidney Stones Go to page

Cats whose bloodwork rises suddenly may have kidney stones. [To be expanded upon]

Summary

OK, so that is your CKD crammer. To recap:

Your cat has to eat. You are going to make sure s/he takes in some food, no matter what it is. You will work on switching to better foods later.
If your cat is vomiting (especially white foam) and/or has a poor appetite, you are going to try treating for stomach acid to see if that helps.
If your cat is at risk of dehydration, you are going to speak to your vet about starting sub-Qs.
If your cat has constipation, you will speak to your vet about using a treatment such as Lactulose, Miralax or Slippery Elm Bark.
If your cat's potassium level is below 4, you are going to ask your vet for a potassium supplement. If your cat's potassium level is above 6, you are going to ask your vet to re-run the test because most probably it is a false reading.
If your cat's phosphorus level is above 6, you are going to ask your vet about using a phosphorus binder.
If your cat's blood pressure is above 160, or if your vet cannot measure your cat's blood pressure but there are serious symptoms such as blindness, you are going to speak to your vet about starting a medication called amlodipine.
If your cat has anaemia, you are going to speak to your vet about treating it. If your cat's PCV or HCT is above 20% but still below normal, you will ask about using a vitamin B and iron supplement. If your cat's PCV is 15-19%, in addition to these treatments you will speak to your vet about whether to use human erythropoietin such as Epogen or Eprex. If your cat's PCV or HCT is below 15%, you will also ask your vet whether your cat might need a blood transfusion to tide him/her over until the other treatments kick in.

CKD can be very complicated, but the above issues are the most critical. Getting any of these issues which are present under control will greatly increase your cat's comfort and chances of living a long, happy life despite the CKD. Try to treat your cat for at least two weeks and see how things go. With the proper treatments and a bit of luck on your side, your cat should be doing a lot, lot better two weeks from now. In the meantime, continue to explore this site - perhaps move onto the Just Diagnosed? What You Need To Know First page next. And if you want to know how bad your cat's numbers are, see the How Bad Is My Cat's Case? page but don't be too discouraged if your cat's numbers seem high - the numbers only tell part of the story.

If you would like some support as you set off on your CKD journey, come and join us at Tanya's CRF Support Group.

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This page last updated: 05 September 2011

Links on this page last checked: 29 July 2010