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Elaine's Avatar
Catsey Veteran
Cats owned: 2 moggies
Join Date: Oct 2005
Location: Aberdeen, Scotland
Posts: 15,256
09-12-2007, 10:39 PM   #1

Chronic Renal Failure

Chronic Renal Failure, Winston’s Legacy

If you are reading this, your cat has probably been diagnosed with CRF. Your cat may be newly diagnosed or has been fighting this disease for some time.
You undoubtedly feel overwhelmed, frightened and emotionally devastated by the news. Don’t beat yourself up about not noticing anything sooner; cats are masters at masking until they can hide it no longer.

CRF is a very complex issue and all things are relevant. I have tried to keep it as simple and easy to understand as I could. CRF is a progressive, terminal illness and not usually an immediate death sentence. Most CRF cats can go on to live for quite some time. I would like to offer some hope and support where I can.

Winston was 18 and half years old when he was diagnosed. My vet offered me little hope, so I set off, heartbroken, and started to read and learn as much as I possibly could about CRF and am still learning today. It’s not all plain sailing and we had many emotional pit falls but Winston’s quality of life was good and we shared each others lives for another 2 and half years. Winston died at the grand old age of 21 on
April 4th 2006.

I am not a vet nor am I an expert on CRF but wanted to share what I have learned and try to explain in layman’s terms. I hope this may help you and your cat.


CRF or Chronic Renal Failure is, in my opinion, a little misleading and I prefer to use the term Insufficiency as opposed to Failure.
It’s a term that classifies kidney problems, which eventually results in kidney function being lost.
As kidney function is lost cats are unable to filter, process and eliminate waste products effectively, resulting in a build up of toxins in the blood stream, making your cat feel very sick.


The signs can often be very subtle but usually include some or all of the following.

An increased thirst and/or urination

Loss of appetite


Weight loss

Dull coat

If you think your cat may have CRF, a trip to the vets for a blood and/or urine test will confirm this.


Many vets still talk very negatively about CRF from the start which doesn’t instil much hope or confidence in the owner. It is important that you and your vet can talk openly and honestly with each other thus creating a good working relationship for the benefit of the cat.
Change vets or get a second opinion. Many vets are not very experienced with CRF, or they think that the owners won’t do what is necessary to help and care for a CRF cat.
No one can tell you how long your cat can live with CRF. Some cats may go down hill fast, while others may go on for years. Even cats with high kidney values can sometimes go on to live for quite some time.
Ask for a copy of the blood results and ask your vet to explain the values to you, and what your options are.

You know your cat better than any one else so follow your instincts.


Urea, when protein is broken down through the digestive process, ammonia is absorbed into the gut. The liver then makes a substance call urea from the ammonia. The urea then travels through the blood stream in the form of urea nitrogen to the kidneys, the blood is filtered out and the rest is filtered out as urine. This means that the urea test is to check the level of nitrogen in the bloodstream.

Creatinine is another waste product which is filtered through the kidneys. Creatinine can tell us more accurately of underlying kidney issues because diet, dehydration and stress affect it less.
Many vets will tell you these values and then tell you what the normal ranges are. It’s scary because it sounds like your cat’s values are exceptionally high. By doing this, your vet isn’t giving you a good reference.
Each cat is different. These values are variable and can be reduced with treatment or at least stabilised. Some cats are able to tolerate mid to high levels of Creatinine and Urea quite well.

Normal ranges vary slightly from lab’ to lab’ but the copy you receive from your vet will give you the normal range for that lab’ and will indicate whether your cat is within normal range or not.

For example
Normal ranges Urea = 3.5 – 8.0 mmol/L Creatinine = 40 – 180

Winston was stable for over a year with a Urea of 18mmol/L and Creatinine of 360 – 377
Although these numbers look high, Winston was comfortable. He had off days but mostly he was on good form.


It’s always best to introduce new foods gradually. There are some mixed opinions about prescription food for CRF cats. The important thing is that your cat eats. If your cat won’t eat the prescribed food, try to find a food with the lowest phosphorus that your cat will eat. Senior cat foods tend to have less phosphorus than Adult cat foods. You may also want to discuss the use of phos binders with your vet. A phos binder will bind the phosphorus in the food in the intestine and stops it from being absorbed. A cat with CRF can‘t excrete phosphorus from its kidneys properly, this in turn may affect calcium levels which can have serious consequences. High levels of phosphorus will make your CRF cat feel very sick. It is recommended that the phosphorus level in the food you choose for your CRF cat should be under 1%, most prescription foods have a phosphorus level of under 0.5%.


It’s very upsetting and frustrating when your cat refuses to eat. You may want to try the following.

Mixing some chicken or tuna into your cat’s food.

Try a variety of foods.

Sit with and talk to your cat while it’s eating.

Excess tummy acid is a big issue with CRF cats, ask your vet about Zantac syrup or similar to help settle your cats tummy.

Slippery Elm Bark may also be useful to help combat tummy acid.

Try mixing some tuna and water together.

Try warming the food or adding a little boiled water to it.

Try assist feeding, sometimes if you can get a little food into your cat, he/she may start to eat on their own. Syringe a little food into the side of the mouth and not directly down the cat’s throat.

You may also want to ask your vet about appetite stimulants.


CRF cats are very prone to becoming anaemic. This can be life threatening and must be taken seriously and treated.
PCV and HCT are both values that can indicate anaemia. Your vet can prescribe Epogen or similar to help with this but my favourite is a supplement of B vits and Iron in the form of Pet Tinnic.


CRF cats may have or at some stage get a secondary illness such as Hyperthyroidism or high blood pressure, in some cases the CRF is actually the secondary illness. The important thing is to keep a watchful eye for any changes in behaviour and general demeanour. If you are unhappy or worried about anything, however small and insignificant, get it checked out. I said it before and I’ll say it again, you are your cats advocate, you know them better than any one and you are the best judge of what is right and wrong.


This is of course a very difficult time. Some say you will know instinctively, others that their cat let them know. It may be an idea to think about PTS before the time actually arrives. Talk to your vet and ask for their guidance. It’s very rare that a CRF cat will die peacefully in its sleep.
With Winston, it was under discussion for a week or two before; his age and ability to cope, as well as his quality of life were all considered. He was almost 21 years old and frail, his world had become so very small and he barely moved from the bed at this stage. He just seemed miserable and the bad times had now out weighed the good times. I couldn’t watch him suffer any more, despite my best efforts to help him. Sadly, the day after his 21st birthday, I let him go. He had had a long and happy life.


Read as much as you can and learn fast. Don’t be afraid to ask questions.
There is a wealth of information on the internet about CRF. Try a Google search for Feline CRF and you will be faced with more sites than you could shake a stick at.

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Az's Avatar
Az Az is offline
Admin Team
Cats owned: Bengal
Join Date: Oct 2005
Location: South Wales UK
Posts: 1,606
Az is Male
28-12-2007, 03:59 AM   #2

Re: Chronic Renal Failure

Thanks for the info Elaine!

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Mags's Avatar
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28-12-2007, 12:56 PM   #3

Re: Chronic Renal Failure

An excellent article Elaine, well written and easy to follow due to your unfortunate experience of it with Winston..

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Kazz's Avatar
Catsey Veteran
Cats owned: Non at the moment
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Location: Planet Earth
Posts: 16,941
28-12-2007, 04:57 PM   #4

Re: Chronic Renal Failure

Really excellent article. Sound advice especially this sentence you are your cats advocate, you know them better than any one and you are the best judge of what is right and wrong.

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angieh's Avatar
Catsey Veteran
Cats owned: Magnificent moggies
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Location: Hampshire, UK
Posts: 21,718
28-12-2007, 07:30 PM   #5

Re: Chronic Renal Failure

Yes, this is an excellent article, Elaine and it is the reason I joined Catsey as it came up when I googled Feline CRF way back in October.

Thanks Elaine!

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Elaine's Avatar
Catsey Veteran
Cats owned: 2 moggies
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Location: Aberdeen, Scotland
Posts: 15,256
28-12-2007, 08:06 PM   #6

Re: Chronic Renal Failure


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Phoenix's Avatar
Catsey Veteran
Cats owned: 2 cats black/white and one tabby
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16-06-2008, 03:55 PM   #7

Re: Chronic Renal Failure

Thank You!

This will be useful for Beauty!

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Catsey Junior
Cats owned: Short haired cross
Join Date: Jul 2011
Location: London, UK
Posts: 65
07-07-2011, 09:33 PM   #8

Re: Chronic Renal Failure

When I had my last cat put down, she was sixteen years old. She had CRF the vet told me. I left the cat at the vet for a few days, and I after treatment she rallied round. We went home with a new diet for the cat, and I was hopeful.

However, a couple of weeks later, she went downhill, and the vet said it would be kinder to put her down. I loved the cat, so I agreed.

If the cat I had now was diagnosed with CRF, this article gives such insight into the condition. It is empowering to a pet owner (imagine if I had read the article and realised that I could get a second opinion?).


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Elaine's Avatar
Catsey Veteran
Cats owned: 2 moggies
Join Date: Oct 2005
Location: Aberdeen, Scotland
Posts: 15,256
07-07-2011, 09:43 PM   #9

Re: Chronic Renal Failure

Dont beat yourself up with what might have been, you acted in the best interests of your cat.
CRF cats can and often do crash, they can look like this is the end but a few days of quality care, understanding of the illness and the symptoms you are treating, the cat can and often does rally round again and remain pretty well until the next little episode.
These episodes can be anything from just feeling really sick and lethargic, dehydration to urine infections, high blood pressure and more serious conditions. You have to be vigilant and treat everything accordingly.
There are times when it is kinder to say goodbye.

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Catsey Junior
Cats owned: Short haired cross
Join Date: Jul 2011
Location: London, UK
Posts: 65
07-07-2011, 10:47 PM   #10

Re: Chronic Renal Failure

You're right. I did do what I felt was best for my cat when I had her put down. You know yourself, that along with the feelings of loss are also a feeling of relief, because you were suffering right along with your cat. Thanks for saying that.

It still stands though, that the cat I have now will be treated differently in the area of CRF, should it ever happen.

Knowledge is a wonderful thing.

Thanks for the article.

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